Revert "remove toString"

This reverts commit 5191880cbf3ee4d122b0d11b4945fbab0784fda7.

Reason for revert: broke flutter

Original change's description:
> remove toString
> 
> toString may have been used by obsolete debugger only
> find out if that is so
> 
> R=​brianosman@google.com,bsalomon@google.com
> 
> Docs-Preview: https://skia.org/?cl=119894
> Bug:830651
> Change-Id: I737f19b7d3fbc869bea2f443fa3b5ed7c1393ffd
> Reviewed-on: https://skia-review.googlesource.com/119894
> Commit-Queue: Cary Clark <caryclark@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>

TBR=bsalomon@google.com,brianosman@google.com,caryclark@google.com,caryclark@skia.org

Change-Id: I9f81de6c3615ee0608bcea9081b77239b4b8816c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 830651
Reviewed-on: https://skia-review.googlesource.com/129340
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Cary Clark <caryclark@google.com>
diff --git a/src/core/SkBitmap.cpp b/src/core/SkBitmap.cpp
index 9151000..5795733 100644
--- a/src/core/SkBitmap.cpp
+++ b/src/core/SkBitmap.cpp
@@ -633,6 +633,33 @@
 }
 #endif
 
+#include "SkString.h"
+void SkBitmap::toString(SkString* str) const {
+
+    static const char* gColorTypeNames[kLastEnum_SkColorType + 1] = {
+        "UNKNOWN", "A8", "565", "4444", "RGBA", "BGRA", "INDEX8",
+    };
+
+    str->appendf("bitmap: ((%d, %d) %s", this->width(), this->height(),
+                 gColorTypeNames[this->colorType()]);
+
+    str->append(" (");
+    if (this->isOpaque()) {
+        str->append("opaque");
+    } else {
+        str->append("transparent");
+    }
+    if (this->isImmutable()) {
+        str->append(", immutable");
+    } else {
+        str->append(", not-immutable");
+    }
+    str->append(")");
+
+    str->appendf(" pixelref:%p", this->pixelRef());
+    str->append(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 bool SkBitmap::peekPixels(SkPixmap* pmap) const {
diff --git a/src/core/SkBlitter.cpp b/src/core/SkBlitter.cpp
index 44cc8f1..5cf8147 100644
--- a/src/core/SkBlitter.cpp
+++ b/src/core/SkBlitter.cpp
@@ -861,6 +861,19 @@
         typedef Context INHERITED;
     };
 
+    void toString(SkString* str) const override {
+        str->append("Sk3DShader: (");
+
+        if (fProxy) {
+            str->append("Proxy: ");
+            as_SB(fProxy)->toString(str);
+        }
+
+        this->INHERITED::toString(str);
+
+        str->append(")");
+    }
+
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(Sk3DShader)
 
 protected:
diff --git a/src/core/SkBlurImageFilter.cpp b/src/core/SkBlurImageFilter.cpp
index 8186448..a53d061 100644
--- a/src/core/SkBlurImageFilter.cpp
+++ b/src/core/SkBlurImageFilter.cpp
@@ -41,6 +41,7 @@
 
     SkRect computeFastBounds(const SkRect&) const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBlurImageFilterImpl)
 
 protected:
@@ -696,3 +697,15 @@
     SkVector sigma = map_sigma(fSigma, ctm);
     return src.makeOutset(SkScalarCeilToInt(sigma.x() * 3), SkScalarCeilToInt(sigma.y() * 3));
 }
+
+void SkBlurImageFilterImpl::toString(SkString* str) const {
+    str->appendf("SkBlurImageFilterImpl: (");
+    str->appendf("sigma: (%f, %f) tileMode: %d input (", fSigma.fWidth, fSigma.fHeight,
+                 static_cast<int>(fTileMode));
+
+    if (this->getInput(0)) {
+        this->getInput(0)->toString(str);
+    }
+
+    str->append("))");
+}
diff --git a/src/core/SkBlurMF.cpp b/src/core/SkBlurMF.cpp
index 23cca83..d716c33 100644
--- a/src/core/SkBlurMF.cpp
+++ b/src/core/SkBlurMF.cpp
@@ -77,6 +77,7 @@
     void computeFastBounds(const SkRect&, SkRect*) const override;
     bool asABlur(BlurRec*) const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBlurMaskFilterImpl)
 
 protected:
@@ -991,6 +992,23 @@
 
 #endif // SK_SUPPORT_GPU
 
+
+void SkBlurMaskFilterImpl::toString(SkString* str) const {
+    str->append("SkBlurMaskFilterImpl: (");
+
+    str->append("sigma: ");
+    str->appendScalar(fSigma);
+    str->append(" ");
+
+    static const char* gStyleName[kLastEnum_SkBlurStyle + 1] = {
+        "normal", "solid", "outer", "inner"
+    };
+
+    str->appendf("style: %s ", gStyleName[fBlurStyle]);
+    str->appendf("respectCTM: %s ", fRespectCTM ? "true" : "false");
+    str->append(")");
+}
+
 void sk_register_blur_maskfilter_createproc() {
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBlurMaskFilterImpl)
 }
diff --git a/src/core/SkColorFilter.cpp b/src/core/SkColorFilter.cpp
index 41ebb42..5362c1a 100644
--- a/src/core/SkColorFilter.cpp
+++ b/src/core/SkColorFilter.cpp
@@ -98,6 +98,15 @@
         return fOuter->getFlags() & fInner->getFlags();
     }
 
+    void toString(SkString* str) const override {
+        SkString outerS, innerS;
+        fOuter->toString(&outerS);
+        fInner->toString(&innerS);
+        // These strings can be long.  SkString::appendf has limitations.
+        str->append(SkStringPrintf("SkComposeColorFilter: outer(%s) inner(%s)", outerS.c_str(),
+                                   innerS.c_str()));
+    }
+
     void onAppendStages(SkRasterPipeline* p, SkColorSpace* dst, SkArenaAlloc* scratch,
                         bool shaderIsOpaque) const override {
         bool innerIsOpaque = shaderIsOpaque;
@@ -216,6 +225,8 @@
     }
 #endif
 
+    void toString(SkString* str) const override;
+
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSRGBGammaColorFilter)
 
     void onAppendStages(SkRasterPipeline* p, SkColorSpace*, SkArenaAlloc* alloc,
@@ -256,6 +267,10 @@
     return sk_sp<SkFlattenable>(new SkSRGBGammaColorFilter(static_cast<Direction>(dir)));
 }
 
+void SkSRGBGammaColorFilter::toString(SkString* str) const {
+    str->append("srgbgamma");
+}
+
 template <SkSRGBGammaColorFilter::Direction dir>
 sk_sp<SkColorFilter> MakeSRGBGammaCF() {
     static SkColorFilter* gSingleton = new SkSRGBGammaColorFilter(dir);
diff --git a/src/core/SkColorMatrixFilterRowMajor255.cpp b/src/core/SkColorMatrixFilterRowMajor255.cpp
index 98fa95a..09b0e76 100644
--- a/src/core/SkColorMatrixFilterRowMajor255.cpp
+++ b/src/core/SkColorMatrixFilterRowMajor255.cpp
@@ -299,6 +299,19 @@
 
 #endif
 
+void SkColorMatrixFilterRowMajor255::toString(SkString* str) const {
+    str->append("SkColorMatrixFilterRowMajor255: ");
+
+    str->append("matrix: (");
+    for (int i = 0; i < 20; ++i) {
+        str->appendScalar(fMatrix[i]);
+        if (i < 19) {
+            str->append(", ");
+        }
+    }
+    str->append(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 sk_sp<SkColorFilter> SkColorFilter::MakeMatrixFilterRowMajor255(const SkScalar array[20]) {
diff --git a/src/core/SkColorMatrixFilterRowMajor255.h b/src/core/SkColorMatrixFilterRowMajor255.h
index c2a38cf..0260379 100644
--- a/src/core/SkColorMatrixFilterRowMajor255.h
+++ b/src/core/SkColorMatrixFilterRowMajor255.h
@@ -27,6 +27,8 @@
             GrContext*, const GrColorSpaceInfo&) const override;
 #endif
 
+    void toString(SkString* str) const override;
+
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkColorMatrixFilter)
 
 protected:
diff --git a/src/core/SkDraw_vertices.cpp b/src/core/SkDraw_vertices.cpp
index de6eaea..000be07 100644
--- a/src/core/SkDraw_vertices.cpp
+++ b/src/core/SkDraw_vertices.cpp
@@ -77,6 +77,8 @@
 
     bool isOpaque() const override { return fIsOpaque; }
 
+    void toString(SkString* str) const override;
+
     // For serialization.  This will never be called.
     Factory getFactory() const override { SK_ABORT("not reached"); return nullptr; }
 
@@ -97,6 +99,14 @@
     typedef SkShaderBase INHERITED;
 };
 
+void SkTriColorShader::toString(SkString* str) const {
+    str->append("SkTriColorShader: (");
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+
 static bool SK_WARN_UNUSED_RESULT
 update_tricolor_matrix(const SkMatrix& ctmInv, const SkPoint pts[], const SkPM4f colors[],
                        int index0, int index1, int index2, Matrix43* result) {
diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 77095fb..aabfef0 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -28,6 +28,35 @@
 #include "SkGr.h"
 #endif
 
+void SkImageFilter::CropRect::toString(SkString* str) const {
+    if (!fFlags) {
+        return;
+    }
+
+    str->appendf("cropRect (");
+    if (fFlags & CropRect::kHasLeft_CropEdge) {
+        str->appendf("%.2f, ", fRect.fLeft);
+    } else {
+        str->appendf("X, ");
+    }
+    if (fFlags & CropRect::kHasTop_CropEdge) {
+        str->appendf("%.2f, ", fRect.fTop);
+    } else {
+        str->appendf("X, ");
+    }
+    if (fFlags & CropRect::kHasWidth_CropEdge) {
+        str->appendf("%.2f, ", fRect.width());
+    } else {
+        str->appendf("X, ");
+    }
+    if (fFlags & CropRect::kHasHeight_CropEdge) {
+        str->appendf("%.2f", fRect.height());
+    } else {
+        str->appendf("X");
+    }
+    str->appendf(") ");
+}
+
 void SkImageFilter::CropRect::applyTo(const SkIRect& imageBounds,
                                       const SkMatrix& ctm,
                                       bool embiggen,
diff --git a/src/core/SkLocalMatrixImageFilter.cpp b/src/core/SkLocalMatrixImageFilter.cpp
index fb484c9..07db7af 100644
--- a/src/core/SkLocalMatrixImageFilter.cpp
+++ b/src/core/SkLocalMatrixImageFilter.cpp
@@ -67,3 +67,8 @@
     }
     return this->refMe();
 }
+
+void SkLocalMatrixImageFilter::toString(SkString* str) const {
+    str->append("SkLocalMatrixImageFilter: (");
+    str->append(")");
+}
diff --git a/src/core/SkLocalMatrixImageFilter.h b/src/core/SkLocalMatrixImageFilter.h
index 79cc73a..89a7e9d 100644
--- a/src/core/SkLocalMatrixImageFilter.h
+++ b/src/core/SkLocalMatrixImageFilter.h
@@ -18,6 +18,7 @@
 public:
     static sk_sp<SkImageFilter> Make(const SkMatrix& localM, sk_sp<SkImageFilter> input);
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLocalMatrixImageFilter)
 
 protected:
diff --git a/src/core/SkMaskFilter.cpp b/src/core/SkMaskFilter.cpp
index 3ff4f93..52cdc3c 100644
--- a/src/core/SkMaskFilter.cpp
+++ b/src/core/SkMaskFilter.cpp
@@ -405,6 +405,7 @@
     }
 
     SkMask::Format getFormat() const override { return SkMask::kA8_Format; }
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposeMF)
 
 protected:
@@ -469,6 +470,10 @@
     return SkMaskFilter::MakeCompose(std::move(outer), std::move(inner));
 }
 
+void SkComposeMF::toString(SkString* str) const {
+    str->set("SkComposeMF:");
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 class SkCombineMF : public SkMaskFilterBase {
@@ -493,6 +498,7 @@
 
     SkMask::Format getFormat() const override { return SkMask::kA8_Format; }
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkCombineMF)
 
 protected:
@@ -619,6 +625,10 @@
     return SkMaskFilter::MakeCombine(std::move(dst), std::move(src), mode);
 }
 
+void SkCombineMF::toString(SkString* str) const {
+    str->set("SkCombineMF:");
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 class SkMatrixMF : public SkMaskFilterBase {
@@ -642,6 +652,10 @@
 
     SkMask::Format getFormat() const override { return as_MFB(fFilter)->getFormat(); }
 
+    void toString(SkString* str) const override {
+        str->set("SkMatrixMF:");
+    }
+
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLocalMatrixMF)
 
 protected:
diff --git a/src/core/SkMatrix.cpp b/src/core/SkMatrix.cpp
index d3bdb38..990f5b4 100644
--- a/src/core/SkMatrix.cpp
+++ b/src/core/SkMatrix.cpp
@@ -1659,10 +1659,14 @@
 
 void SkMatrix::dump() const {
     SkString str;
-    str.appendf("[%8.4f %8.4f %8.4f][%8.4f %8.4f %8.4f][%8.4f %8.4f %8.4f]",
+    this->toString(&str);
+    SkDebugf("%s\n", str.c_str());
+}
+
+void SkMatrix::toString(SkString* str) const {
+    str->appendf("[%8.4f %8.4f %8.4f][%8.4f %8.4f %8.4f][%8.4f %8.4f %8.4f]",
              fMat[0], fMat[1], fMat[2], fMat[3], fMat[4], fMat[5],
              fMat[6], fMat[7], fMat[8]);
-    SkDebugf("%s\n", str.c_str());
 }
 
 ///////////////////////////////////////////////////////////////////////////////
diff --git a/src/core/SkMatrixImageFilter.cpp b/src/core/SkMatrixImageFilter.cpp
index e56abbc..47b0d42 100644
--- a/src/core/SkMatrixImageFilter.cpp
+++ b/src/core/SkMatrixImageFilter.cpp
@@ -143,3 +143,25 @@
 
     return result;
 }
+
+void SkMatrixImageFilter::toString(SkString* str) const {
+    str->appendf("SkMatrixImageFilter: (");
+
+    str->appendf("transform: (%f %f %f %f %f %f %f %f %f)",
+                 fTransform[SkMatrix::kMScaleX],
+                 fTransform[SkMatrix::kMSkewX],
+                 fTransform[SkMatrix::kMTransX],
+                 fTransform[SkMatrix::kMSkewY],
+                 fTransform[SkMatrix::kMScaleY],
+                 fTransform[SkMatrix::kMTransY],
+                 fTransform[SkMatrix::kMPersp0],
+                 fTransform[SkMatrix::kMPersp1],
+                 fTransform[SkMatrix::kMPersp2]);
+
+    str->append("<dt>FilterLevel:</dt><dd>");
+    static const char* gFilterLevelStrings[] = { "None", "Low", "Medium", "High" };
+    str->append(gFilterLevelStrings[fFilterQuality]);
+    str->append("</dd>");
+
+    str->appendf(")");
+}
diff --git a/src/core/SkMatrixImageFilter.h b/src/core/SkMatrixImageFilter.h
index 1a6bcf5..b43df91 100644
--- a/src/core/SkMatrixImageFilter.h
+++ b/src/core/SkMatrixImageFilter.h
@@ -31,6 +31,7 @@
 
     SkRect computeFastBounds(const SkRect&) const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkMatrixImageFilter)
 
 protected:
diff --git a/src/core/SkModeColorFilter.cpp b/src/core/SkModeColorFilter.cpp
index 7e1e26e..b3d6aa2 100644
--- a/src/core/SkModeColorFilter.cpp
+++ b/src/core/SkModeColorFilter.cpp
@@ -31,6 +31,13 @@
     fPMColor = SkPreMultiplyColor(fColor);
 }
 
+void SkModeColorFilter::toString(SkString* str) const {
+    str->append("SkModeColorFilter: color: 0x");
+    str->appendHex(fColor);
+    str->append(" mode: ");
+    str->append(SkBlendMode_Name(fMode));
+}
+
 bool SkModeColorFilter::asColorMode(SkColor* color, SkBlendMode* mode) const {
     if (color) {
         *color = fColor;
diff --git a/src/core/SkModeColorFilter.h b/src/core/SkModeColorFilter.h
index 025839f..a2a629f 100644
--- a/src/core/SkModeColorFilter.h
+++ b/src/core/SkModeColorFilter.h
@@ -22,6 +22,8 @@
     bool asColorMode(SkColor*, SkBlendMode*) const override;
     uint32_t getFlags() const override;
 
+    void toString(SkString* str) const override;
+
 #if SK_SUPPORT_GPU
     std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(
             GrContext*, const GrColorSpaceInfo&) const override;
diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index c76b981..82dec0ea 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -1384,6 +1384,155 @@
     return *storage;
 }
 
+void SkPaint::toString(SkString* str) const {
+    str->append("<dl><dt>SkPaint:</dt><dd><dl>");
+
+    SkTypeface* typeface = this->getTypeface();
+    if (typeface) {
+        SkDynamicMemoryWStream ostream;
+        typeface->serialize(&ostream);
+        std::unique_ptr<SkStreamAsset> istream(ostream.detachAsStream());
+
+        SkFontDescriptor descriptor;
+        if (!SkFontDescriptor::Deserialize(istream.get(), &descriptor)) {
+            str->append("<dt>FontDescriptor deserialization failed</dt>");
+        } else {
+            str->append("<dt>Font Family Name:</dt><dd>");
+            str->append(descriptor.getFamilyName());
+            str->append("</dd><dt>Font Full Name:</dt><dd>");
+            str->append(descriptor.getFullName());
+            str->append("</dd><dt>Font PS Name:</dt><dd>");
+            str->append(descriptor.getPostscriptName());
+            str->append("</dd>");
+        }
+    }
+
+    str->append("<dt>TextSize:</dt><dd>");
+    str->appendScalar(this->getTextSize());
+    str->append("</dd>");
+
+    str->append("<dt>TextScaleX:</dt><dd>");
+    str->appendScalar(this->getTextScaleX());
+    str->append("</dd>");
+
+    str->append("<dt>TextSkewX:</dt><dd>");
+    str->appendScalar(this->getTextSkewX());
+    str->append("</dd>");
+
+    SkPathEffect* pathEffect = this->getPathEffect();
+    if (pathEffect) {
+        str->append("<dt>PathEffect:</dt><dd>");
+        pathEffect->toString(str);
+        str->append("</dd>");
+    }
+
+    if (const auto* shader = as_SB(this->getShader())) {
+        str->append("<dt>Shader:</dt><dd>");
+        shader->toString(str);
+        str->append("</dd>");
+    }
+
+    if (!this->isSrcOver()) {
+        str->appendf("<dt>Xfermode:</dt><dd>%d</dd>", fBlendMode);
+    }
+
+    SkMaskFilter* maskFilter = this->getMaskFilter();
+    if (maskFilter) {
+        str->append("<dt>MaskFilter:</dt><dd>");
+        as_MFB(maskFilter)->toString(str);
+        str->append("</dd>");
+    }
+
+    SkColorFilter* colorFilter = this->getColorFilter();
+    if (colorFilter) {
+        str->append("<dt>ColorFilter:</dt><dd>");
+        colorFilter->toString(str);
+        str->append("</dd>");
+    }
+
+    SkDrawLooper* looper = this->getLooper();
+    if (looper) {
+        str->append("<dt>DrawLooper:</dt><dd>");
+        looper->toString(str);
+        str->append("</dd>");
+    }
+
+    SkImageFilter* imageFilter = this->getImageFilter();
+    if (imageFilter) {
+        str->append("<dt>ImageFilter:</dt><dd>");
+        imageFilter->toString(str);
+        str->append("</dd>");
+    }
+
+    str->append("<dt>Color:</dt><dd>0x");
+    SkColor color = this->getColor();
+    str->appendHex(color);
+    str->append("</dd>");
+
+    str->append("<dt>Stroke Width:</dt><dd>");
+    str->appendScalar(this->getStrokeWidth());
+    str->append("</dd>");
+
+    str->append("<dt>Stroke Miter:</dt><dd>");
+    str->appendScalar(this->getStrokeMiter());
+    str->append("</dd>");
+
+    str->append("<dt>Flags:</dt><dd>(");
+    if (this->getFlags()) {
+        bool needSeparator = false;
+        SkAddFlagToString(str, this->isAntiAlias(), "AntiAlias", &needSeparator);
+        SkAddFlagToString(str, this->isDither(), "Dither", &needSeparator);
+        SkAddFlagToString(str, this->isFakeBoldText(), "FakeBoldText", &needSeparator);
+        SkAddFlagToString(str, this->isLinearText(), "LinearText", &needSeparator);
+        SkAddFlagToString(str, this->isSubpixelText(), "SubpixelText", &needSeparator);
+        SkAddFlagToString(str, this->isLCDRenderText(), "LCDRenderText", &needSeparator);
+        SkAddFlagToString(str, this->isEmbeddedBitmapText(),
+                          "EmbeddedBitmapText", &needSeparator);
+        SkAddFlagToString(str, this->isAutohinted(), "Autohinted", &needSeparator);
+        SkAddFlagToString(str, this->isVerticalText(), "VerticalText", &needSeparator);
+    } else {
+        str->append("None");
+    }
+    str->append(")</dd>");
+
+    str->append("<dt>FilterLevel:</dt><dd>");
+    static const char* gFilterQualityStrings[] = { "None", "Low", "Medium", "High" };
+    str->append(gFilterQualityStrings[this->getFilterQuality()]);
+    str->append("</dd>");
+
+    str->append("<dt>TextAlign:</dt><dd>");
+    static const char* gTextAlignStrings[SkPaint::kAlignCount] = { "Left", "Center", "Right" };
+    str->append(gTextAlignStrings[this->getTextAlign()]);
+    str->append("</dd>");
+
+    str->append("<dt>CapType:</dt><dd>");
+    static const char* gStrokeCapStrings[SkPaint::kCapCount] = { "Butt", "Round", "Square" };
+    str->append(gStrokeCapStrings[this->getStrokeCap()]);
+    str->append("</dd>");
+
+    str->append("<dt>JoinType:</dt><dd>");
+    static const char* gJoinStrings[SkPaint::kJoinCount] = { "Miter", "Round", "Bevel" };
+    str->append(gJoinStrings[this->getStrokeJoin()]);
+    str->append("</dd>");
+
+    str->append("<dt>Style:</dt><dd>");
+    static const char* gStyleStrings[SkPaint::kStyleCount] = { "Fill", "Stroke", "StrokeAndFill" };
+    str->append(gStyleStrings[this->getStyle()]);
+    str->append("</dd>");
+
+    str->append("<dt>TextEncoding:</dt><dd>");
+    static const char* gTextEncodingStrings[] = { "UTF8", "UTF16", "UTF32", "GlyphID" };
+    str->append(gTextEncodingStrings[this->getTextEncoding()]);
+    str->append("</dd>");
+
+    str->append("<dt>Hinting:</dt><dd>");
+    static const char* gHintingStrings[] = { "None", "Slight", "Normal", "Full" };
+    str->append(gHintingStrings[this->getHinting()]);
+    str->append("</dd>");
+
+    str->append("</dd></dl></dl>");
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 static bool has_thick_frame(const SkPaint& paint) {
diff --git a/src/core/SkPathEffect.cpp b/src/core/SkPathEffect.cpp
index e315275..09d7e54 100644
--- a/src/core/SkPathEffect.cpp
+++ b/src/core/SkPathEffect.cpp
@@ -51,10 +51,23 @@
     sk_sp<SkPathEffect> fPE0;
     sk_sp<SkPathEffect> fPE1;
 
+    void toString(SkString* str) const override;
+
 private:
     typedef SkPathEffect INHERITED;
 };
 
+void SkPairPathEffect::toString(SkString* str) const {
+    str->appendf("first: ");
+    if (fPE0) {
+        fPE0->toString(str);
+    }
+    str->appendf(" second: ");
+    if (fPE1) {
+        fPE1->toString(str);
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 /** \class SkComposePathEffect
@@ -91,6 +104,7 @@
     }
 
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposePathEffect)
 
 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
@@ -116,6 +130,12 @@
     return SkComposePathEffect::Make(std::move(pe0), std::move(pe1));
 }
 
+void SkComposePathEffect::toString(SkString* str) const {
+    str->appendf("SkComposePathEffect: (");
+    this->INHERITED::toString(str);
+    str->appendf(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 /** \class SkSumPathEffect
@@ -148,6 +168,7 @@
     }
 
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSumPathEffect)
 
 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
@@ -173,6 +194,12 @@
     return SkSumPathEffect::Make(pe0, pe1);
 }
 
+void SkSumPathEffect::toString(SkString* str) const {
+    str->appendf("SkSumPathEffect: (");
+    this->INHERITED::toString(str);
+    str->appendf(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 sk_sp<SkPathEffect> SkPathEffect::MakeSum(sk_sp<SkPathEffect> first, sk_sp<SkPathEffect> second) {
diff --git a/src/core/SkStringUtils.cpp b/src/core/SkStringUtils.cpp
index 00d8c87..9745b23 100644
--- a/src/core/SkStringUtils.cpp
+++ b/src/core/SkStringUtils.cpp
@@ -9,6 +9,16 @@
 #include "SkStringUtils.h"
 #include "SkUtils.h"
 
+void SkAddFlagToString(SkString* string, bool flag, const char* flagStr, bool* needSeparator) {
+    if (flag) {
+        if (*needSeparator) {
+            string->append("|");
+        }
+        string->append(flagStr);
+        *needSeparator = true;
+    }
+}
+
 void SkAppendScalar(SkString* str, SkScalar value, SkScalarAsStringType asType) {
     switch (asType) {
         case kHex_SkScalarAsStringType:
diff --git a/src/core/SkStringUtils.h b/src/core/SkStringUtils.h
index ac587d6..f2a1443 100644
--- a/src/core/SkStringUtils.h
+++ b/src/core/SkStringUtils.h
@@ -12,6 +12,16 @@
 
 class SkString;
 
+/**
+ * Add 'flagStr' to 'string' and set 'needSeparator' to true only if 'flag' is
+ * true. If 'needSeparator' is true append a '|' before 'flagStr'. This method
+ * is used to streamline the creation of ASCII flag strings within the toString
+ * methods.
+ */
+void SkAddFlagToString(SkString* string, bool flag,
+                       const char* flagStr, bool* needSeparator);
+
+
 enum SkScalarAsStringType {
     kDec_SkScalarAsStringType,
     kHex_SkScalarAsStringType,
diff --git a/src/effects/Sk1DPathEffect.cpp b/src/effects/Sk1DPathEffect.cpp
index 1837479..57f2d2b 100644
--- a/src/effects/Sk1DPathEffect.cpp
+++ b/src/effects/Sk1DPathEffect.cpp
@@ -194,6 +194,14 @@
     return fAdvance;
 }
 
+
+void SkPath1DPathEffect::toString(SkString* str) const {
+    str->appendf("SkPath1DPathEffect: (");
+    // TODO: add path and style
+    str->appendf("advance: %.2f phase %.2f", fAdvance, fInitialOffset);
+    str->appendf(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 sk_sp<SkPathEffect> SkPath1DPathEffect::Make(const SkPath& path, SkScalar advance, SkScalar phase,
diff --git a/src/effects/Sk2DPathEffect.cpp b/src/effects/Sk2DPathEffect.cpp
index 6c2c4c2..a541b91 100644
--- a/src/effects/Sk2DPathEffect.cpp
+++ b/src/effects/Sk2DPathEffect.cpp
@@ -74,6 +74,13 @@
     buffer.writeMatrix(fMatrix);
 }
 
+void Sk2DPathEffect::toString(SkString* str) const {
+    str->appendf("(matrix: %.2f %.2f %.2f %.2f %.2f %.2f %.2f %.2f %.2f)",
+            fMatrix[SkMatrix::kMScaleX], fMatrix[SkMatrix::kMSkewX],  fMatrix[SkMatrix::kMTransX],
+            fMatrix[SkMatrix::kMSkewY],  fMatrix[SkMatrix::kMScaleY], fMatrix[SkMatrix::kMTransY],
+            fMatrix[SkMatrix::kMPersp0], fMatrix[SkMatrix::kMPersp1], fMatrix[SkMatrix::kMPersp2]);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 bool SkLine2DPathEffect::filterPath(SkPath* dst, const SkPath& src,
@@ -110,6 +117,14 @@
     buffer.writeScalar(fWidth);
 }
 
+
+void SkLine2DPathEffect::toString(SkString* str) const {
+    str->appendf("SkLine2DPathEffect: (");
+    this->INHERITED::toString(str);
+    str->appendf("width: %f", fWidth);
+    str->appendf(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 SkPath2DPathEffect::SkPath2DPathEffect(const SkMatrix& m, const SkPath& p)
@@ -133,3 +148,11 @@
                               SkPath* dst) const {
     dst->addPath(fPath, loc.fX, loc.fY);
 }
+
+void SkPath2DPathEffect::toString(SkString* str) const {
+    str->appendf("SkPath2DPathEffect: (");
+    this->INHERITED::toString(str);
+    // TODO: print out path information
+    str->appendf(")");
+}
+
diff --git a/src/effects/SkAlphaThresholdFilter.cpp b/src/effects/SkAlphaThresholdFilter.cpp
index 5bd2571..f09ec50 100644
--- a/src/effects/SkAlphaThresholdFilter.cpp
+++ b/src/effects/SkAlphaThresholdFilter.cpp
@@ -31,6 +31,7 @@
                                SkScalar outerThreshold, sk_sp<SkImageFilter> input,
                                const CropRect* cropRect = nullptr);
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkAlphaThresholdFilterImpl)
     friend void SkAlphaThresholdFilter::InitializeFlattenables();
 
@@ -280,3 +281,10 @@
     }
     return this->refMe();
 }
+
+void SkAlphaThresholdFilterImpl::toString(SkString* str) const {
+    str->appendf("SkAlphaThresholdImageFilter: (");
+    str->appendf("inner: %f outer: %f", fInnerThreshold, fOuterThreshold);
+    str->append(")");
+}
+
diff --git a/src/effects/SkArithmeticImageFilter.cpp b/src/effects/SkArithmeticImageFilter.cpp
index 578cc0d..c022ec9 100644
--- a/src/effects/SkArithmeticImageFilter.cpp
+++ b/src/effects/SkArithmeticImageFilter.cpp
@@ -37,6 +37,7 @@
                               sk_sp<SkImageFilter> inputs[2], const CropRect* cropRect)
             : INHERITED(inputs, 2, cropRect), fK{k1, k2, k3, k4}, fEnforcePMColor(enforcePMColor) {}
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(ArithmeticImageFilterImpl)
 
 protected:
@@ -431,6 +432,22 @@
     return this->refMe();
 }
 
+void ArithmeticImageFilterImpl::toString(SkString* str) const {
+    str->appendf("SkArithmeticImageFilter: (");
+    str->appendf("K[]: (%f %f %f %f)", fK[0], fK[1], fK[2], fK[3]);
+    if (this->getInput(0)) {
+        str->appendf("foreground: (");
+        this->getInput(0)->toString(str);
+        str->appendf(")");
+    }
+    if (this->getInput(1)) {
+        str->appendf("background: (");
+        this->getInput(1)->toString(str);
+        str->appendf(")");
+    }
+    str->append(")");
+}
+
 sk_sp<SkImageFilter> SkArithmeticImageFilter::Make(float k1, float k2, float k3, float k4,
                                                    bool enforcePMColor,
                                                    sk_sp<SkImageFilter> background,
diff --git a/src/effects/SkColorFilterImageFilter.cpp b/src/effects/SkColorFilterImageFilter.cpp
index 9bea794..514d046 100644
--- a/src/effects/SkColorFilterImageFilter.cpp
+++ b/src/effects/SkColorFilterImageFilter.cpp
@@ -144,3 +144,18 @@
 bool SkColorFilterImageFilter::affectsTransparentBlack() const {
     return fColorFilter->affectsTransparentBlack();
 }
+
+void SkColorFilterImageFilter::toString(SkString* str) const {
+    str->appendf("SkColorFilterImageFilter: (");
+
+    str->appendf("input: (");
+
+    if (this->getInput(0)) {
+        this->getInput(0)->toString(str);
+    }
+
+    str->appendf(") color filter: ");
+    fColorFilter->toString(str);
+
+    str->append(")");
+}
diff --git a/src/effects/SkColorMatrixFilter.cpp b/src/effects/SkColorMatrixFilter.cpp
index c68c47e..7a562b4 100644
--- a/src/effects/SkColorMatrixFilter.cpp
+++ b/src/effects/SkColorMatrixFilter.cpp
@@ -72,6 +72,8 @@
     }
 #endif
 
+    void toString(SkString* str) const override { fMatrixFilter->toString(str); }
+
 private:
     SkColor              fMul, fAdd;
     sk_sp<SkColorFilter> fMatrixFilter;
diff --git a/src/effects/SkComposeImageFilter.cpp b/src/effects/SkComposeImageFilter.cpp
index 842588d..51cec9c 100644
--- a/src/effects/SkComposeImageFilter.cpp
+++ b/src/effects/SkComposeImageFilter.cpp
@@ -88,3 +88,17 @@
     return SkComposeImageFilter::Make(common.getInput(0), common.getInput(1));
 }
 
+void SkComposeImageFilter::toString(SkString* str) const {
+    SkImageFilter* outer = getInput(0);
+    SkImageFilter* inner = getInput(1);
+
+    str->appendf("SkComposeImageFilter: (");
+
+    str->appendf("outer: ");
+    outer->toString(str);
+
+    str->appendf("inner: ");
+    inner->toString(str);
+
+    str->appendf(")");
+}
diff --git a/src/effects/SkCornerPathEffect.cpp b/src/effects/SkCornerPathEffect.cpp
index a88bc32..ec137b9 100644
--- a/src/effects/SkCornerPathEffect.cpp
+++ b/src/effects/SkCornerPathEffect.cpp
@@ -151,3 +151,9 @@
 void SkCornerPathEffect::flatten(SkWriteBuffer& buffer) const {
     buffer.writeScalar(fRadius);
 }
+
+void SkCornerPathEffect::toString(SkString* str) const {
+    str->appendf("SkCornerPathEffect: (");
+    str->appendf("radius: %.2f", fRadius);
+    str->appendf(")");
+}
diff --git a/src/effects/SkDashImpl.h b/src/effects/SkDashImpl.h
index f2c8255..f5c4244 100644
--- a/src/effects/SkDashImpl.h
+++ b/src/effects/SkDashImpl.h
@@ -21,6 +21,7 @@
 
     DashType asADash(DashInfo* info) const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDashImpl)
 
 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
diff --git a/src/effects/SkDashPathEffect.cpp b/src/effects/SkDashPathEffect.cpp
index 7f003da..cdadcf9 100644
--- a/src/effects/SkDashPathEffect.cpp
+++ b/src/effects/SkDashPathEffect.cpp
@@ -380,6 +380,18 @@
     return nullptr;
 }
 
+void SkDashImpl::toString(SkString* str) const {
+    str->appendf("SkDashPathEffect: (");
+    str->appendf("count: %d phase %.2f intervals: (", fCount, fPhase);
+    for (int i = 0; i < fCount; ++i) {
+        str->appendf("%.2f", fIntervals[i]);
+        if (i < fCount-1) {
+            str->appendf(", ");
+        }
+    }
+    str->appendf("))");
+}
+
 //////////////////////////////////////////////////////////////////////////////////////////////////
 
 sk_sp<SkPathEffect> SkDashPathEffect::Make(const SkScalar intervals[], int count, SkScalar phase) {
diff --git a/src/effects/SkDiscretePathEffect.cpp b/src/effects/SkDiscretePathEffect.cpp
index 46cd42b..57d8f96 100644
--- a/src/effects/SkDiscretePathEffect.cpp
+++ b/src/effects/SkDiscretePathEffect.cpp
@@ -143,3 +143,9 @@
     buffer.writeScalar(fPerterb);
     buffer.writeUInt(fSeedAssist);
 }
+
+void SkDiscretePathEffect::toString(SkString* str) const {
+    str->appendf("SkDiscretePathEffect: (");
+    str->appendf("segLength: %.2f deviation: %.2f seed %d", fSegLength, fPerterb, fSeedAssist);
+    str->append(")");
+}
diff --git a/src/effects/SkDisplacementMapEffect.cpp b/src/effects/SkDisplacementMapEffect.cpp
index 9dcf0be..d40e521 100644
--- a/src/effects/SkDisplacementMapEffect.cpp
+++ b/src/effects/SkDisplacementMapEffect.cpp
@@ -404,6 +404,20 @@
     return src;
 }
 
+void SkDisplacementMapEffect::toString(SkString* str) const {
+    str->appendf("SkDisplacementMapEffect: (");
+    str->appendf("scale: %f ", fScale);
+    str->appendf("displacement: (");
+    if (this->getDisplacementInput()) {
+        this->getDisplacementInput()->toString(str);
+    }
+    str->appendf(") color: (");
+    if (this->getColorInput()) {
+        this->getColorInput()->toString(str);
+    }
+    str->appendf("))");
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 #if SK_SUPPORT_GPU
diff --git a/src/effects/SkDropShadowImageFilter.cpp b/src/effects/SkDropShadowImageFilter.cpp
index d19c05f..7532894 100644
--- a/src/effects/SkDropShadowImageFilter.cpp
+++ b/src/effects/SkDropShadowImageFilter.cpp
@@ -159,3 +159,24 @@
     return dst;
 }
 
+void SkDropShadowImageFilter::toString(SkString* str) const {
+    str->appendf("SkDropShadowImageFilter: (");
+
+    str->appendf("dX: %f ", fDx);
+    str->appendf("dY: %f ", fDy);
+    str->appendf("sigmaX: %f ", fSigmaX);
+    str->appendf("sigmaY: %f ", fSigmaY);
+
+    str->append("Color: ");
+    str->appendHex(fColor);
+
+    static const char* gModeStrings[] = {
+        "kDrawShadowAndForeground", "kDrawShadowOnly"
+    };
+
+    static_assert(kShadowModeCount == SK_ARRAY_COUNT(gModeStrings), "enum_mismatch");
+
+    str->appendf(" mode: %s", gModeStrings[fShadowMode]);
+
+    str->append(")");
+}
diff --git a/src/effects/SkEmbossMaskFilter.cpp b/src/effects/SkEmbossMaskFilter.cpp
index ef26520..4a4c8d0 100644
--- a/src/effects/SkEmbossMaskFilter.cpp
+++ b/src/effects/SkEmbossMaskFilter.cpp
@@ -140,3 +140,22 @@
     buffer.writeByteArray(&tmpLight, sizeof(tmpLight));
     buffer.writeScalar(fBlurSigma);
 }
+
+void SkEmbossMaskFilter::toString(SkString* str) const {
+    str->append("SkEmbossMaskFilter: (");
+
+    str->append("direction: (");
+    str->appendScalar(fLight.fDirection[0]);
+    str->append(", ");
+    str->appendScalar(fLight.fDirection[1]);
+    str->append(", ");
+    str->appendScalar(fLight.fDirection[2]);
+    str->append(") ");
+
+    str->appendf("ambient: %d specular: %d ",
+        fLight.fAmbient, fLight.fSpecular);
+
+    str->append("blurSigma: ");
+    str->appendScalar(fBlurSigma);
+    str->append(")");
+}
diff --git a/src/effects/SkEmbossMaskFilter.h b/src/effects/SkEmbossMaskFilter.h
index 9c3cb62..bc992a0 100644
--- a/src/effects/SkEmbossMaskFilter.h
+++ b/src/effects/SkEmbossMaskFilter.h
@@ -32,6 +32,7 @@
     bool filterMask(SkMask* dst, const SkMask& src, const SkMatrix&,
                     SkIPoint* margin) const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkEmbossMaskFilter)
 
 protected:
diff --git a/src/effects/SkHighContrastFilter.cpp b/src/effects/SkHighContrastFilter.cpp
index 607033e..b805212 100644
--- a/src/effects/SkHighContrastFilter.cpp
+++ b/src/effects/SkHighContrastFilter.cpp
@@ -45,6 +45,8 @@
                         SkArenaAlloc* scratch,
                         bool shaderIsOpaque) const override;
 
+    void toString(SkString* str) const override;
+
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkHighContrast_Filter)
 
 protected:
@@ -155,6 +157,10 @@
     return sk_make_sp<SkHighContrast_Filter>(config);
 }
 
+void SkHighContrast_Filter::toString(SkString* str) const {
+    str->append("SkHighContrastColorFilter ");
+}
+
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkHighContrastFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkHighContrast_Filter)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
diff --git a/src/effects/SkImageSource.cpp b/src/effects/SkImageSource.cpp
index 960de37..0f48fb0 100644
--- a/src/effects/SkImageSource.cpp
+++ b/src/effects/SkImageSource.cpp
@@ -157,3 +157,12 @@
     return dstRect.roundOut();
 }
 
+void SkImageSource::toString(SkString* str) const {
+    str->appendf("SkImageSource: (");
+    str->appendf("src: (%f,%f,%f,%f) dst: (%f,%f,%f,%f) ",
+                 fSrcRect.fLeft, fSrcRect.fTop, fSrcRect.fRight, fSrcRect.fBottom,
+                 fDstRect.fLeft, fDstRect.fTop, fDstRect.fRight, fDstRect.fBottom);
+    str->appendf("image: (%d,%d)",
+                 fImage->width(), fImage->height());
+    str->append(")");
+}
diff --git a/src/effects/SkLayerDrawLooper.cpp b/src/effects/SkLayerDrawLooper.cpp
index 16108094..db61e08 100644
--- a/src/effects/SkLayerDrawLooper.cpp
+++ b/src/effects/SkLayerDrawLooper.cpp
@@ -279,6 +279,62 @@
     return builder.detach();
 }
 
+void SkLayerDrawLooper::toString(SkString* str) const {
+    str->appendf("SkLayerDrawLooper (%d): ", fCount);
+
+    Rec* rec = fRecs;
+    for (int i = 0; i < fCount; i++) {
+        str->appendf("%d: paintBits: (", i);
+        if (0 == rec->fInfo.fPaintBits) {
+            str->append("None");
+        } else if (kEntirePaint_Bits == rec->fInfo.fPaintBits) {
+            str->append("EntirePaint");
+        } else {
+            bool needSeparator = false;
+            SkAddFlagToString(str, SkToBool(kStyle_Bit & rec->fInfo.fPaintBits), "Style",
+                              &needSeparator);
+            SkAddFlagToString(str, SkToBool(kTextSkewX_Bit & rec->fInfo.fPaintBits), "TextSkewX",
+                              &needSeparator);
+            SkAddFlagToString(str, SkToBool(kPathEffect_Bit & rec->fInfo.fPaintBits), "PathEffect",
+                              &needSeparator);
+            SkAddFlagToString(str, SkToBool(kMaskFilter_Bit & rec->fInfo.fPaintBits), "MaskFilter",
+                              &needSeparator);
+            SkAddFlagToString(str, SkToBool(kShader_Bit & rec->fInfo.fPaintBits), "Shader",
+                              &needSeparator);
+            SkAddFlagToString(str, SkToBool(kColorFilter_Bit & rec->fInfo.fPaintBits), "ColorFilter",
+                              &needSeparator);
+            SkAddFlagToString(str, SkToBool(kXfermode_Bit & rec->fInfo.fPaintBits), "Xfermode",
+                              &needSeparator);
+        }
+        str->append(") ");
+
+        static const char* gModeStrings[(int)SkBlendMode::kLastMode+1] = {
+            "kClear", "kSrc", "kDst", "kSrcOver", "kDstOver", "kSrcIn", "kDstIn",
+            "kSrcOut", "kDstOut", "kSrcATop", "kDstATop", "kXor", "kPlus",
+            "kMultiply", "kScreen", "kOverlay", "kDarken", "kLighten", "kColorDodge",
+            "kColorBurn", "kHardLight", "kSoftLight", "kDifference", "kExclusion"
+        };
+
+        str->appendf("mode: %s ", gModeStrings[(int)rec->fInfo.fColorMode]);
+
+        str->append("offset: (");
+        str->appendScalar(rec->fInfo.fOffset.fX);
+        str->append(", ");
+        str->appendScalar(rec->fInfo.fOffset.fY);
+        str->append(") ");
+
+        str->append("postTranslate: ");
+        if (rec->fInfo.fPostTranslate) {
+            str->append("true ");
+        } else {
+            str->append("false ");
+        }
+
+        rec->fPaint.toString(str);
+        rec = rec->fNext;
+    }
+}
+
 SkLayerDrawLooper::Builder::Builder()
         : fRecs(nullptr),
           fTopRec(nullptr),
diff --git a/src/effects/SkLightingImageFilter.cpp b/src/effects/SkLightingImageFilter.cpp
index c812cce..0a13305 100644
--- a/src/effects/SkLightingImageFilter.cpp
+++ b/src/effects/SkLightingImageFilter.cpp
@@ -530,6 +530,7 @@
                                      sk_sp<SkImageFilter>,
                                      const CropRect*);
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDiffuseLightingImageFilter)
     SkScalar kd() const { return fKD; }
 
@@ -564,6 +565,7 @@
                                      SkScalar ks, SkScalar shininess,
                                      sk_sp<SkImageFilter>, const CropRect*);
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSpecularLightingImageFilter)
 
     SkScalar ks() const { return fKS; }
@@ -1369,6 +1371,12 @@
     return this->refMe();
 }
 
+void SkDiffuseLightingImageFilter::toString(SkString* str) const {
+    str->appendf("SkDiffuseLightingImageFilter: (");
+    str->appendf("kD: %f\n", fKD);
+    str->append(")");
+}
+
 #if SK_SUPPORT_GPU
 std::unique_ptr<GrFragmentProcessor> SkDiffuseLightingImageFilter::makeFragmentProcessor(
         sk_sp<GrTextureProxy> proxy,
@@ -1518,6 +1526,12 @@
     return this->refMe();
 }
 
+void SkSpecularLightingImageFilter::toString(SkString* str) const {
+    str->appendf("SkSpecularLightingImageFilter: (");
+    str->appendf("kS: %f shininess: %f", fKS, fShininess);
+    str->append(")");
+}
+
 #if SK_SUPPORT_GPU
 std::unique_ptr<GrFragmentProcessor> SkSpecularLightingImageFilter::makeFragmentProcessor(
         sk_sp<GrTextureProxy> proxy,
diff --git a/src/effects/SkLumaColorFilter.cpp b/src/effects/SkLumaColorFilter.cpp
index 12d6dd8..847d5f9 100644
--- a/src/effects/SkLumaColorFilter.cpp
+++ b/src/effects/SkLumaColorFilter.cpp
@@ -37,6 +37,10 @@
 
 void SkLumaColorFilter::flatten(SkWriteBuffer&) const {}
 
+void SkLumaColorFilter::toString(SkString* str) const {
+    str->append("SkLumaColorFilter ");
+}
+
 #if SK_SUPPORT_GPU
 std::unique_ptr<GrFragmentProcessor> SkLumaColorFilter::asFragmentProcessor(
         GrContext*, const GrColorSpaceInfo&) const {
diff --git a/src/effects/SkMagnifierImageFilter.cpp b/src/effects/SkMagnifierImageFilter.cpp
index e28469e..75e9817 100644
--- a/src/effects/SkMagnifierImageFilter.cpp
+++ b/src/effects/SkMagnifierImageFilter.cpp
@@ -200,3 +200,11 @@
     }
     return this->refMe();
 }
+
+void SkMagnifierImageFilter::toString(SkString* str) const {
+    str->appendf("SkMagnifierImageFilter: (");
+    str->appendf("src: (%f,%f,%f,%f) ",
+                 fSrcRect.fLeft, fSrcRect.fTop, fSrcRect.fRight, fSrcRect.fBottom);
+    str->appendf("inset: %f", fInset);
+    str->append(")");
+}
diff --git a/src/effects/SkMatrixConvolutionImageFilter.cpp b/src/effects/SkMatrixConvolutionImageFilter.cpp
index 7668a02..848676a 100644
--- a/src/effects/SkMatrixConvolutionImageFilter.cpp
+++ b/src/effects/SkMatrixConvolutionImageFilter.cpp
@@ -479,3 +479,18 @@
     // pixels it will affect in object-space.
     return kRepeat_TileMode != fTileMode;
 }
+
+void SkMatrixConvolutionImageFilter::toString(SkString* str) const {
+    str->appendf("SkMatrixConvolutionImageFilter: (");
+    str->appendf("size: (%d,%d) kernel: (", fKernelSize.width(), fKernelSize.height());
+    for (int y = 0; y < fKernelSize.height(); y++) {
+        for (int x = 0; x < fKernelSize.width(); x++) {
+            str->appendf("%f ", fKernel[y * fKernelSize.width() + x]);
+        }
+    }
+    str->appendf(")");
+    str->appendf("gain: %f bias: %f ", fGain, fBias);
+    str->appendf("offset: (%d, %d) ", fKernelOffset.fX, fKernelOffset.fY);
+    str->appendf("convolveAlpha: %s", fConvolveAlpha ? "true" : "false");
+    str->append(")");
+}
diff --git a/src/effects/SkMergeImageFilter.cpp b/src/effects/SkMergeImageFilter.cpp
index 633ddd4..41d545e 100644
--- a/src/effects/SkMergeImageFilter.cpp
+++ b/src/effects/SkMergeImageFilter.cpp
@@ -121,3 +121,15 @@
     this->INHERITED::flatten(buffer);
 }
 
+void SkMergeImageFilter::toString(SkString* str) const {
+    str->appendf("SkMergeImageFilter: (");
+
+    for (int i = 0; i < this->countInputs(); ++i) {
+        SkImageFilter* filter = this->getInput(i);
+        str->appendf("%d: (", i);
+        filter->toString(str);
+        str->appendf(")");
+    }
+
+    str->append(")");
+}
diff --git a/src/effects/SkMorphologyImageFilter.cpp b/src/effects/SkMorphologyImageFilter.cpp
index d46364a..e421fdd 100644
--- a/src/effects/SkMorphologyImageFilter.cpp
+++ b/src/effects/SkMorphologyImageFilter.cpp
@@ -113,6 +113,18 @@
     return Make(width, height, common.getInput(0), &common.cropRect());
 }
 
+void SkErodeImageFilter::toString(SkString* str) const {
+    str->appendf("SkErodeImageFilter: (");
+    str->appendf("radius: (%d,%d)", this->radius().fWidth, this->radius().fHeight);
+    str->append(")");
+}
+
+void SkDilateImageFilter::toString(SkString* str) const {
+    str->appendf("SkDilateImageFilter: (");
+    str->appendf("radius: (%d,%d)", this->radius().fWidth, this->radius().fHeight);
+    str->append(")");
+}
+
 #if SK_SUPPORT_GPU
 
 ///////////////////////////////////////////////////////////////////////////////
diff --git a/src/effects/SkOffsetImageFilter.cpp b/src/effects/SkOffsetImageFilter.cpp
index 25b7289..5b1533b 100644
--- a/src/effects/SkOffsetImageFilter.cpp
+++ b/src/effects/SkOffsetImageFilter.cpp
@@ -124,3 +124,13 @@
     : INHERITED(&input, 1, cropRect) {
     fOffset.set(dx, dy);
 }
+
+void SkOffsetImageFilter::toString(SkString* str) const {
+    str->appendf("SkOffsetImageFilter: (");
+    str->appendf("offset: (%f, %f) ", fOffset.fX, fOffset.fY);
+    str->append("input: (");
+    if (this->getInput(0)) {
+        this->getInput(0)->toString(str);
+    }
+    str->append("))");
+}
diff --git a/src/effects/SkOverdrawColorFilter.cpp b/src/effects/SkOverdrawColorFilter.cpp
index 71dbb72..01dab65 100644
--- a/src/effects/SkOverdrawColorFilter.cpp
+++ b/src/effects/SkOverdrawColorFilter.cpp
@@ -36,6 +36,14 @@
     p->append(SkRasterPipeline::callback, ctx);
 }
 
+void SkOverdrawColorFilter::toString(SkString* str) const {
+    str->append("SkOverdrawColorFilter (");
+    for (int i = 0; i < kNumColors; i++) {
+        str->appendf("%d: %x\n", i, fColors[i]);
+    }
+    str->append(")");
+}
+
 void SkOverdrawColorFilter::flatten(SkWriteBuffer& buffer) const {
     buffer.writeByteArray(fColors, kNumColors * sizeof(SkPMColor));
 }
diff --git a/src/effects/SkPaintImageFilter.cpp b/src/effects/SkPaintImageFilter.cpp
index c0be41f..235f76f 100644
--- a/src/effects/SkPaintImageFilter.cpp
+++ b/src/effects/SkPaintImageFilter.cpp
@@ -81,3 +81,9 @@
 bool SkPaintImageFilter::affectsTransparentBlack() const {
     return true;
 }
+
+void SkPaintImageFilter::toString(SkString* str) const {
+    str->appendf("SkPaintImageFilter: (");
+    fPaint.toString(str);
+    str->append(")");
+}
diff --git a/src/effects/SkPictureImageFilter.cpp b/src/effects/SkPictureImageFilter.cpp
index e6069c3..93a494d 100644
--- a/src/effects/SkPictureImageFilter.cpp
+++ b/src/effects/SkPictureImageFilter.cpp
@@ -130,3 +130,15 @@
 
     return sk_sp<SkImageFilter>(new SkPictureImageFilter(fPicture, fCropRect, std::move(dstCS)));
 }
+
+void SkPictureImageFilter::toString(SkString* str) const {
+    str->appendf("SkPictureImageFilter: (");
+    str->appendf("crop: (%f,%f,%f,%f) ",
+                 fCropRect.fLeft, fCropRect.fTop, fCropRect.fRight, fCropRect.fBottom);
+    if (fPicture) {
+        str->appendf("picture: (%f,%f,%f,%f)",
+                     fPicture->cullRect().fLeft, fPicture->cullRect().fTop,
+                     fPicture->cullRect().fRight, fPicture->cullRect().fBottom);
+    }
+    str->append(")");
+}
diff --git a/src/effects/SkShaderMaskFilter.cpp b/src/effects/SkShaderMaskFilter.cpp
index f2160a1..cfa15c5 100644
--- a/src/effects/SkShaderMaskFilter.cpp
+++ b/src/effects/SkShaderMaskFilter.cpp
@@ -27,6 +27,7 @@
 
     bool asABlur(BlurRec*) const override { return false; }
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkShaderMF)
 
 protected:
@@ -46,6 +47,10 @@
     typedef SkMaskFilter INHERITED;
 };
 
+void SkShaderMF::toString(SkString* str) const {
+    str->set("SkShaderMF:");
+}
+
 sk_sp<SkFlattenable> SkShaderMF::CreateProc(SkReadBuffer& buffer) {
     return SkShaderMaskFilter::Make(buffer.readShader());
 }
diff --git a/src/effects/SkTableColorFilter.cpp b/src/effects/SkTableColorFilter.cpp
index fcf76dc..47d6ae2 100644
--- a/src/effects/SkTableColorFilter.cpp
+++ b/src/effects/SkTableColorFilter.cpp
@@ -90,6 +90,8 @@
             GrContext*, const GrColorSpaceInfo&) const override;
 #endif
 
+    void toString(SkString* str) const override;
+
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTable_ColorFilter)
 
     enum {
@@ -138,6 +140,35 @@
     typedef SkColorFilter INHERITED;
 };
 
+void SkTable_ColorFilter::toString(SkString* str) const {
+    const uint8_t* table = fStorage;
+    const uint8_t* tableA = gIdentityTable;
+    const uint8_t* tableR = gIdentityTable;
+    const uint8_t* tableG = gIdentityTable;
+    const uint8_t* tableB = gIdentityTable;
+    if (fFlags & kA_Flag) {
+        tableA = table; table += 256;
+    }
+    if (fFlags & kR_Flag) {
+        tableR = table; table += 256;
+    }
+    if (fFlags & kG_Flag) {
+        tableG = table; table += 256;
+    }
+    if (fFlags & kB_Flag) {
+        tableB = table;
+    }
+
+    str->append("SkTable_ColorFilter (");
+
+    for (int i = 0; i < 256; ++i) {
+        str->appendf("%d: %d,%d,%d,%d\n",
+                     i, tableR[i], tableG[i], tableB[i], tableA[i]);
+    }
+
+    str->append(")");
+}
+
 static const uint8_t gCountNibBits[] = {
     0, 1, 1, 2,
     1, 2, 2, 3,
diff --git a/src/effects/SkTableMaskFilter.cpp b/src/effects/SkTableMaskFilter.cpp
index 8ff58ec..2df2fa7 100644
--- a/src/effects/SkTableMaskFilter.cpp
+++ b/src/effects/SkTableMaskFilter.cpp
@@ -18,6 +18,7 @@
     SkMask::Format getFormat() const override;
     bool filterMask(SkMask*, const SkMask&, const SkMatrix&, SkIPoint*) const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTableMaskFilterImpl)
 
 protected:
@@ -166,3 +167,15 @@
     SkDebugf("\n\n");
 #endif
 }
+
+void SkTableMaskFilterImpl::toString(SkString* str) const {
+    str->append("SkTableMaskFilter: (");
+
+    str->append("table: ");
+    for (int i = 0; i < 255; ++i) {
+        str->appendf("%d, ", fTable[i]);
+    }
+    str->appendf("%d", fTable[255]);
+
+    str->append(")");
+}
diff --git a/src/effects/SkTileImageFilter.cpp b/src/effects/SkTileImageFilter.cpp
index eddad27..1aac581 100644
--- a/src/effects/SkTileImageFilter.cpp
+++ b/src/effects/SkTileImageFilter.cpp
@@ -157,3 +157,17 @@
     buffer.writeRect(fSrcRect);
     buffer.writeRect(fDstRect);
 }
+
+void SkTileImageFilter::toString(SkString* str) const {
+    str->appendf("SkTileImageFilter: (");
+    str->appendf("src: %.2f %.2f %.2f %.2f",
+                 fSrcRect.fLeft, fSrcRect.fTop, fSrcRect.fRight, fSrcRect.fBottom);
+    str->appendf(" dst: %.2f %.2f %.2f %.2f",
+                 fDstRect.fLeft, fDstRect.fTop, fDstRect.fRight, fDstRect.fBottom);
+    if (this->getInput(0)) {
+        str->appendf("input: (");
+        this->getInput(0)->toString(str);
+        str->appendf(")");
+    }
+    str->append(")");
+}
diff --git a/src/effects/SkToSRGBColorFilter.cpp b/src/effects/SkToSRGBColorFilter.cpp
index 09acabf..d2020ef 100644
--- a/src/effects/SkToSRGBColorFilter.cpp
+++ b/src/effects/SkToSRGBColorFilter.cpp
@@ -71,6 +71,11 @@
     buffer.writeDataAsByteArray(fSrcColorSpace->serialize().get());
 }
 
+void SkToSRGBColorFilter::toString(SkString* str) const {
+    // TODO
+    str->append("SkToSRGBColorFilter ");
+}
+
 #if SK_SUPPORT_GPU
 std::unique_ptr<GrFragmentProcessor> SkToSRGBColorFilter::asFragmentProcessor(
         GrContext*, const GrColorSpaceInfo&) const {
diff --git a/src/effects/SkTrimPE.h b/src/effects/SkTrimPE.h
index f66bccc..7a05e72 100644
--- a/src/effects/SkTrimPE.h
+++ b/src/effects/SkTrimPE.h
@@ -18,6 +18,7 @@
 
     bool filterPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect*) const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTrimPE)
 
 protected:
diff --git a/src/effects/SkTrimPathEffect.cpp b/src/effects/SkTrimPathEffect.cpp
index 8c3f56e..d63393a 100644
--- a/src/effects/SkTrimPathEffect.cpp
+++ b/src/effects/SkTrimPathEffect.cpp
@@ -97,6 +97,10 @@
         (mode & 1) ? SkTrimPathEffect::Mode::kInverted : SkTrimPathEffect::Mode::kNormal);
 }
 
+void SkTrimPE::toString(SkString* str) const {
+    str->appendf("SkTrimPathEffect: (%g %g)", fStartT, fStopT);
+}
+
 //////////////////////////////////////////////////////////////////////////////////////////////////
 
 sk_sp<SkPathEffect> SkTrimPathEffect::Make(SkScalar startT, SkScalar stopT, Mode mode) {
diff --git a/src/effects/SkXfermodeImageFilter.cpp b/src/effects/SkXfermodeImageFilter.cpp
index ff4a629..9123818 100644
--- a/src/effects/SkXfermodeImageFilter.cpp
+++ b/src/effects/SkXfermodeImageFilter.cpp
@@ -34,6 +34,7 @@
     SkXfermodeImageFilter_Base(SkBlendMode mode, sk_sp<SkImageFilter> inputs[2],
                                const CropRect* cropRect);
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkXfermodeImageFilter_Base)
 
 protected:
@@ -248,6 +249,22 @@
     canvas->drawPaint(paint);
 }
 
+void SkXfermodeImageFilter_Base::toString(SkString* str) const {
+    str->appendf("SkXfermodeImageFilter: (");
+    str->appendf("blendmode: (%d)", (int)fMode);
+    if (this->getInput(0)) {
+        str->appendf("foreground: (");
+        this->getInput(0)->toString(str);
+        str->appendf(")");
+    }
+    if (this->getInput(1)) {
+        str->appendf("background: (");
+        this->getInput(1)->toString(str);
+        str->appendf(")");
+    }
+    str->append(")");
+}
+
 #if SK_SUPPORT_GPU
 
 #include "effects/GrXfermodeFragmentProcessor.h"
diff --git a/src/gpu/GrTestUtils.h b/src/gpu/GrTestUtils.h
index 7627df4..0cfe6e4 100644
--- a/src/gpu/GrTestUtils.h
+++ b/src/gpu/GrTestUtils.h
@@ -74,6 +74,7 @@
     bool filterPath(SkPath* dst, const SkPath&, SkStrokeRec* , const SkRect*) const override;
     DashType asADash(DashInfo* info) const override;
     Factory getFactory() const override { return nullptr; }
+    void toString(SkString*) const override {}
 
 private:
     TestDashPathEffect(const SkScalar* intervals, int count, SkScalar phase);
diff --git a/src/gpu/text/GrSDFMaskFilter.cpp b/src/gpu/text/GrSDFMaskFilter.cpp
index 82adaaa..ff79cdb 100644
--- a/src/gpu/text/GrSDFMaskFilter.cpp
+++ b/src/gpu/text/GrSDFMaskFilter.cpp
@@ -26,6 +26,7 @@
 
     void computeFastBounds(const SkRect&, SkRect*) const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(GrSDFMaskFilterImpl)
 
 protected:
@@ -86,6 +87,10 @@
     return GrSDFMaskFilter::Make();
 }
 
+void GrSDFMaskFilterImpl::toString(SkString* str) const {
+    str->append("GrSDFMaskFilterImpl: ()");
+}
+
 void gr_register_sdf_maskfilter_createproc() {
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(GrSDFMaskFilterImpl)
 }
diff --git a/src/image/SkImage.cpp b/src/image/SkImage.cpp
index b57f727..3be804f 100644
--- a/src/image/SkImage.cpp
+++ b/src/image/SkImage.cpp
@@ -132,6 +132,12 @@
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
+const char* SkImage::toString(SkString* str) const {
+    str->appendf("image: (id:%d (%d, %d) %s)", this->uniqueID(), this->width(), this->height(),
+                 this->isOpaque() ? "opaque" : "");
+    return str->c_str();
+}
+
 sk_sp<SkImage> SkImage::makeSubset(const SkIRect& subset) const {
     if (subset.isEmpty()) {
         return nullptr;
diff --git a/src/shaders/SkColorFilterShader.cpp b/src/shaders/SkColorFilterShader.cpp
index 16bf565..0f25518 100644
--- a/src/shaders/SkColorFilterShader.cpp
+++ b/src/shaders/SkColorFilterShader.cpp
@@ -71,6 +71,19 @@
 }
 #endif
 
+void SkColorFilterShader::toString(SkString* str) const {
+    str->append("SkColorFilterShader: (");
+
+    str->append("Shader: ");
+    as_SB(fShader)->toString(str);
+    str->append(" Filter: ");
+    // TODO: add "fFilter->toString(str);" once SkColorFilter::toString is added
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 sk_sp<SkShader> SkShader::makeWithColorFilter(sk_sp<SkColorFilter> filter) const {
diff --git a/src/shaders/SkColorFilterShader.h b/src/shaders/SkColorFilterShader.h
index d97dd06..2f5b469 100644
--- a/src/shaders/SkColorFilterShader.h
+++ b/src/shaders/SkColorFilterShader.h
@@ -21,6 +21,7 @@
     std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs&) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkColorFilterShader)
 
 protected:
diff --git a/src/shaders/SkColorShader.cpp b/src/shaders/SkColorShader.cpp
index c3f86b9..152a0b5 100644
--- a/src/shaders/SkColorShader.cpp
+++ b/src/shaders/SkColorShader.cpp
@@ -97,6 +97,17 @@
 
 #endif
 
+void SkColorShader::toString(SkString* str) const {
+    str->append("SkColorShader: (");
+
+    str->append("Color: ");
+    str->appendHex(fColor);
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
@@ -212,6 +223,16 @@
 
 #endif
 
+void SkColor4Shader::toString(SkString* str) const {
+    str->append("SkColor4Shader: (");
+
+    str->append("RGBA:");
+    for (int i = 0; i < 4; ++i) {
+        str->appendf(" %g", fColor4.vec()[i]);
+    }
+    str->append(" )");
+}
+
 sk_sp<SkShader> SkColor4Shader::onMakeColorSpace(SkColorSpaceXformer* xformer) const {
     return SkShader::MakeColorShader(xformer->apply(fCachedByteColor));
 }
diff --git a/src/shaders/SkColorShader.h b/src/shaders/SkColorShader.h
index 235f8e3..9fab094 100644
--- a/src/shaders/SkColorShader.h
+++ b/src/shaders/SkColorShader.h
@@ -50,6 +50,7 @@
     std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs&) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkColorShader)
 
 protected:
@@ -105,6 +106,7 @@
     std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs&) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkColorShader)
 
 protected:
diff --git a/src/shaders/SkComposeShader.cpp b/src/shaders/SkComposeShader.cpp
index 845d320..e7125ad 100644
--- a/src/shaders/SkComposeShader.cpp
+++ b/src/shaders/SkComposeShader.cpp
@@ -141,3 +141,18 @@
                                                               std::move(fpA), fMode);
 }
 #endif
+
+void SkComposeShader::toString(SkString* str) const {
+    str->append("SkComposeShader: (");
+
+    str->append("dst: ");
+    as_SB(fDst)->toString(str);
+    str->append(" src: ");
+    as_SB(fSrc)->toString(str);
+    str->appendf(" mode: %s", SkBlendMode_Name(fMode));
+    str->appendf(" lerpT: %g", fLerpT);
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
diff --git a/src/shaders/SkComposeShader.h b/src/shaders/SkComposeShader.h
index c2dc2c3..9208502 100644
--- a/src/shaders/SkComposeShader.h
+++ b/src/shaders/SkComposeShader.h
@@ -35,6 +35,7 @@
     bool asACompose(ComposeRec* rec) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposeShader)
 
 protected:
diff --git a/src/shaders/SkEmptyShader.h b/src/shaders/SkEmptyShader.h
index 7956003..12848b37 100644
--- a/src/shaders/SkEmptyShader.h
+++ b/src/shaders/SkEmptyShader.h
@@ -20,6 +20,7 @@
 public:
     SkEmptyShader() {}
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkEmptyShader)
 
 protected:
diff --git a/src/shaders/SkImageShader.cpp b/src/shaders/SkImageShader.cpp
index 7744f89..8ef647f 100644
--- a/src/shaders/SkImageShader.cpp
+++ b/src/shaders/SkImageShader.cpp
@@ -173,6 +173,17 @@
     return sk_sp<SkShader>{ new SkImageShader(image, tx,ty, localMatrix, clampAsIfUnpremul) };
 }
 
+void SkImageShader::toString(SkString* str) const {
+    const char* gTileModeName[SkShader::kTileModeCount] = {
+        "clamp", "repeat", "mirror"
+    };
+
+    str->appendf("ImageShader: ((%s %s) ", gTileModeName[fTileModeX], gTileModeName[fTileModeY]);
+    fImage->toString(str);
+    this->INHERITED::toString(str);
+    str->append(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 #if SK_SUPPORT_GPU
diff --git a/src/shaders/SkImageShader.h b/src/shaders/SkImageShader.h
index 0d40c23..3e980d3 100644
--- a/src/shaders/SkImageShader.h
+++ b/src/shaders/SkImageShader.h
@@ -23,6 +23,7 @@
 
     bool isOpaque() const override;
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkImageShader)
 
 #if SK_SUPPORT_GPU
diff --git a/src/shaders/SkLocalMatrixShader.cpp b/src/shaders/SkLocalMatrixShader.cpp
index 28d7775..509c66d 100644
--- a/src/shaders/SkLocalMatrixShader.cpp
+++ b/src/shaders/SkLocalMatrixShader.cpp
@@ -71,6 +71,16 @@
     return as_SB(fProxyShader)->appendStages(newRec);
 }
 
+void SkLocalMatrixShader::toString(SkString* str) const {
+    str->append("SkLocalMatrixShader: (");
+
+    as_SB(fProxyShader)->toString(str);
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+
 sk_sp<SkShader> SkShader::makeWithLocalMatrix(const SkMatrix& localMatrix) const {
     if (localMatrix.isIdentity()) {
         return sk_ref_sp(const_cast<SkShader*>(this));
diff --git a/src/shaders/SkLocalMatrixShader.h b/src/shaders/SkLocalMatrixShader.h
index 9f89812..48d1ef1 100644
--- a/src/shaders/SkLocalMatrixShader.h
+++ b/src/shaders/SkLocalMatrixShader.h
@@ -38,6 +38,7 @@
         return fProxyShader;
     }
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLocalMatrixShader)
 
 protected:
diff --git a/src/shaders/SkPerlinNoiseShader.cpp b/src/shaders/SkPerlinNoiseShader.cpp
index b3dc9d4..d864e16 100644
--- a/src/shaders/SkPerlinNoiseShader.cpp
+++ b/src/shaders/SkPerlinNoiseShader.cpp
@@ -364,6 +364,7 @@
     std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs&) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPerlinNoiseShaderImpl)
 
 protected:
@@ -1476,6 +1477,37 @@
 
 #endif
 
+void SkPerlinNoiseShaderImpl::toString(SkString* str) const {
+    str->append("SkPerlinNoiseShaderImpl: (");
+
+    str->append("type: ");
+    switch (fType) {
+        case kFractalNoise_Type:
+            str->append("\"fractal noise\"");
+            break;
+        case kTurbulence_Type:
+            str->append("\"turbulence\"");
+            break;
+        default:
+            str->append("\"unknown\"");
+            break;
+    }
+    str->append(" base frequency: (");
+    str->appendScalar(fBaseFrequencyX);
+    str->append(", ");
+    str->appendScalar(fBaseFrequencyY);
+    str->append(") number of octaves: ");
+    str->appendS32(fNumOctaves);
+    str->append(" seed: ");
+    str->appendScalar(fSeed);
+    str->append(" stitch tiles: ");
+    str->append(fStitchTiles ? "true " : "false ");
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 static bool valid_input(SkScalar baseX, SkScalar baseY, int numOctaves, const SkISize* tileSize,
diff --git a/src/shaders/SkPictureShader.cpp b/src/shaders/SkPictureShader.cpp
index 576598b..f958814 100644
--- a/src/shaders/SkPictureShader.cpp
+++ b/src/shaders/SkPictureShader.cpp
@@ -338,6 +338,22 @@
     fBitmapShaderContext->shadeSpan(x, y, dstC, count);
 }
 
+void SkPictureShader::toString(SkString* str) const {
+    static const char* gTileModeName[SkShader::kTileModeCount] = {
+        "clamp", "repeat", "mirror"
+    };
+
+    str->appendf("PictureShader: [%f:%f:%f:%f] ",
+                 fPicture->cullRect().fLeft,
+                 fPicture->cullRect().fTop,
+                 fPicture->cullRect().fRight,
+                 fPicture->cullRect().fBottom);
+
+    str->appendf("(%s, %s)", gTileModeName[fTmx], gTileModeName[fTmy]);
+
+    this->INHERITED::toString(str);
+}
+
 #if SK_SUPPORT_GPU
 std::unique_ptr<GrFragmentProcessor> SkPictureShader::asFragmentProcessor(
         const GrFPArgs& args) const {
diff --git a/src/shaders/SkPictureShader.h b/src/shaders/SkPictureShader.h
index 25fe53f..6e5201e 100644
--- a/src/shaders/SkPictureShader.h
+++ b/src/shaders/SkPictureShader.h
@@ -28,6 +28,7 @@
     static sk_sp<SkShader> Make(sk_sp<SkPicture>, TileMode, TileMode, const SkMatrix*,
                                 const SkRect*);
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPictureShader)
 
 #if SK_SUPPORT_GPU
diff --git a/src/shaders/SkShader.cpp b/src/shaders/SkShader.cpp
index a17cca1..f3ffd26 100644
--- a/src/shaders/SkShader.cpp
+++ b/src/shaders/SkShader.cpp
@@ -208,6 +208,13 @@
     return SkPictureShader::Make(std::move(src), tmx, tmy, localMatrix, tile);
 }
 
+void SkShaderBase::toString(SkString* str) const {
+    if (!fLocalMatrix.isIdentity()) {
+        str->append(" ");
+        fLocalMatrix.toString(str);
+    }
+}
+
 bool SkShaderBase::appendStages(const StageRec& rec) const {
     return this->onAppendStages(rec);
 }
@@ -251,3 +258,13 @@
 sk_sp<SkFlattenable> SkEmptyShader::CreateProc(SkReadBuffer&) {
     return SkShader::MakeEmptyShader();
 }
+
+#include "SkEmptyShader.h"
+
+void SkEmptyShader::toString(SkString* str) const {
+    str->append("SkEmptyShader: (");
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
diff --git a/src/shaders/SkShaderBase.h b/src/shaders/SkShaderBase.h
index d0b830b..cddc554 100644
--- a/src/shaders/SkShaderBase.h
+++ b/src/shaders/SkShaderBase.h
@@ -207,6 +207,8 @@
         return nullptr;
     }
 
+    virtual void toString(SkString* str) const;
+
     SK_DEFINE_FLATTENABLE_TYPE(SkShaderBase)
     SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
 
diff --git a/src/shaders/gradients/SkGradientShader.cpp b/src/shaders/gradients/SkGradientShader.cpp
index eea70ca..78f514c 100644
--- a/src/shaders/gradients/SkGradientShader.cpp
+++ b/src/shaders/gradients/SkGradientShader.cpp
@@ -626,6 +626,38 @@
     }
 }
 
+void SkGradientShaderBase::toString(SkString* str) const {
+
+    str->appendf("%d colors: ", fColorCount);
+
+    for (int i = 0; i < fColorCount; ++i) {
+        str->appendHex(this->getLegacyColor(i), 8);
+        if (i < fColorCount-1) {
+            str->append(", ");
+        }
+    }
+
+    if (fColorCount > 2) {
+        str->append(" points: (");
+        for (int i = 0; i < fColorCount; ++i) {
+            str->appendScalar(this->getPos(i));
+            if (i < fColorCount-1) {
+                str->append(", ");
+            }
+        }
+        str->append(")");
+    }
+
+    static const char* gTileModeName[SkShader::kTileModeCount] = {
+        "clamp", "repeat", "mirror", "decal",
+    };
+
+    str->append(" ");
+    str->append(gTileModeName[fTileMode]);
+
+    this->INHERITED::toString(str);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/src/shaders/gradients/SkGradientShaderPriv.h b/src/shaders/gradients/SkGradientShaderPriv.h
index e50f1a6..dccb4e7 100644
--- a/src/shaders/gradients/SkGradientShaderPriv.h
+++ b/src/shaders/gradients/SkGradientShaderPriv.h
@@ -80,6 +80,7 @@
 
     SkGradientShaderBase(SkReadBuffer& );
     void flatten(SkWriteBuffer&) const override;
+    void toString(SkString* str) const override;
 
     void commonAsAGradient(GradientInfo*) const;
 
diff --git a/src/shaders/gradients/SkLinearGradient.cpp b/src/shaders/gradients/SkLinearGradient.cpp
index 34cac26..a377442 100644
--- a/src/shaders/gradients/SkLinearGradient.cpp
+++ b/src/shaders/gradients/SkLinearGradient.cpp
@@ -207,4 +207,14 @@
 
 #endif
 
+void SkLinearGradient::toString(SkString* str) const {
+    str->append("SkLinearGradient (");
+
+    str->appendf("start: (%f, %f)", fStart.fX, fStart.fY);
+    str->appendf(" end: (%f, %f) ", fEnd.fX, fEnd.fY);
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
 
diff --git a/src/shaders/gradients/SkLinearGradient.h b/src/shaders/gradients/SkLinearGradient.h
index d100a1c..111ed99 100644
--- a/src/shaders/gradients/SkLinearGradient.h
+++ b/src/shaders/gradients/SkLinearGradient.h
@@ -19,6 +19,7 @@
     std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs&) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkLinearGradient)
 
 protected:
diff --git a/src/shaders/gradients/SkRadialGradient.cpp b/src/shaders/gradients/SkRadialGradient.cpp
index ec0f8a0..6d19361 100644
--- a/src/shaders/gradients/SkRadialGradient.cpp
+++ b/src/shaders/gradients/SkRadialGradient.cpp
@@ -185,3 +185,19 @@
                                             SkRasterPipeline*) const {
     p->append(SkRasterPipeline::xy_to_radius);
 }
+
+void SkRadialGradient::toString(SkString* str) const {
+    str->append("SkRadialGradient: (");
+
+    str->append("center: (");
+    str->appendScalar(fCenter.fX);
+    str->append(", ");
+    str->appendScalar(fCenter.fY);
+    str->append(") radius: ");
+    str->appendScalar(fRadius);
+    str->append(" ");
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
diff --git a/src/shaders/gradients/SkRadialGradient.h b/src/shaders/gradients/SkRadialGradient.h
index d6963f6..b0d6854 100644
--- a/src/shaders/gradients/SkRadialGradient.h
+++ b/src/shaders/gradients/SkRadialGradient.h
@@ -19,6 +19,7 @@
     std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs&) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkRadialGradient)
 
 protected:
diff --git a/src/shaders/gradients/SkSweepGradient.cpp b/src/shaders/gradients/SkSweepGradient.cpp
index cfce5fe..c409d9a 100644
--- a/src/shaders/gradients/SkSweepGradient.cpp
+++ b/src/shaders/gradients/SkSweepGradient.cpp
@@ -241,6 +241,20 @@
                                        fGradFlags, &this->getLocalMatrix());
 }
 
+void SkSweepGradient::toString(SkString* str) const {
+    str->append("SkSweepGradient: (");
+
+    str->append("center: (");
+    str->appendScalar(fCenter.fX);
+    str->append(", ");
+    str->appendScalar(fCenter.fY);
+    str->append(") ");
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+
 void SkSweepGradient::appendGradientStages(SkArenaAlloc* alloc, SkRasterPipeline* p,
                                            SkRasterPipeline*) const {
     p->append(SkRasterPipeline::xy_to_unit_angle);
diff --git a/src/shaders/gradients/SkSweepGradient.h b/src/shaders/gradients/SkSweepGradient.h
index a58c957..dce9a35 100644
--- a/src/shaders/gradients/SkSweepGradient.h
+++ b/src/shaders/gradients/SkSweepGradient.h
@@ -20,6 +20,7 @@
     std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs&) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSweepGradient)
 
 protected:
diff --git a/src/shaders/gradients/SkTwoPointConicalGradient.cpp b/src/shaders/gradients/SkTwoPointConicalGradient.cpp
index 7d5026b..73ec3f2 100644
--- a/src/shaders/gradients/SkTwoPointConicalGradient.cpp
+++ b/src/shaders/gradients/SkTwoPointConicalGradient.cpp
@@ -199,6 +199,31 @@
                                                  fTileMode, fGradFlags, &this->getLocalMatrix());
 }
 
+
+void SkTwoPointConicalGradient::toString(SkString* str) const {
+    str->append("SkTwoPointConicalGradient: (");
+
+    str->append("center1: (");
+    str->appendScalar(fCenter1.fX);
+    str->append(", ");
+    str->appendScalar(fCenter1.fY);
+    str->append(") radius1: ");
+    str->appendScalar(fRadius1);
+    str->append(" ");
+
+    str->append("center2: (");
+    str->appendScalar(fCenter2.fX);
+    str->append(", ");
+    str->appendScalar(fCenter2.fY);
+    str->append(") radius2: ");
+    str->appendScalar(fRadius2);
+    str->append(" ");
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+
 void SkTwoPointConicalGradient::appendGradientStages(SkArenaAlloc* alloc, SkRasterPipeline* p,
                                                      SkRasterPipeline* postPipeline) const {
     const auto dRadius = fRadius2 - fRadius1;
diff --git a/src/shaders/gradients/SkTwoPointConicalGradient.h b/src/shaders/gradients/SkTwoPointConicalGradient.h
index b965e15..f0d341f 100644
--- a/src/shaders/gradients/SkTwoPointConicalGradient.h
+++ b/src/shaders/gradients/SkTwoPointConicalGradient.h
@@ -65,6 +65,7 @@
     const SkMatrix& getGradientMatrix() const { return fPtsToUnit; }
     const FocalData& getFocalData() const { return fFocalData; }
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTwoPointConicalGradient)
 
 protected:
diff --git a/src/utils/SkShadowUtils.cpp b/src/utils/SkShadowUtils.cpp
index 4032ad2..5049dd6 100644
--- a/src/utils/SkShadowUtils.cpp
+++ b/src/utils/SkShadowUtils.cpp
@@ -44,6 +44,7 @@
             GrContext*, const GrColorSpaceInfo&) const override;
 #endif
 
+    void toString(SkString* str) const override;
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkGaussianColorFilter)
 
 protected:
@@ -62,6 +63,10 @@
     return Make();
 }
 
+void SkGaussianColorFilter::toString(SkString* str) const {
+    str->append("SkGaussianColorFilter ");
+}
+
 #if SK_SUPPORT_GPU
 
 std::unique_ptr<GrFragmentProcessor> SkGaussianColorFilter::asFragmentProcessor(