Add SkImageFilter::makeColorSpace(SkColorSpaceXformer*)

Plus two sample implementations.  Will fill out the
rest if the model looks ok.

Bug: skia:
Change-Id: Ie24ecd0cbc36263220cb1e506f7812c582554e50
Reviewed-on: https://skia-review.googlesource.com/12100
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Matt Sarett <msarett@google.com>
diff --git a/src/core/SkColorSpaceXformer.cpp b/src/core/SkColorSpaceXformer.cpp
index 8a83dbc..d256ddf 100644
--- a/src/core/SkColorSpaceXformer.cpp
+++ b/src/core/SkColorSpaceXformer.cpp
@@ -11,6 +11,7 @@
 #include "SkDrawLooper.h"
 #include "SkGradientShader.h"
 #include "SkImage_Base.h"
+#include "SkImageFilter.h"
 #include "SkImagePriv.h"
 #include "SkMakeUnique.h"
 
@@ -172,8 +173,10 @@
         get_dst()->setDrawLooper(looper->makeColorSpace(this));
     }
 
-    // TODO:
-    //    - image filters?
+    if (auto imageFilter = src.getImageFilter()) {
+        get_dst()->setImageFilter(imageFilter->makeColorSpace(this));
+    }
+
     return *result;
 }
 
diff --git a/src/effects/SkArithmeticImageFilter.cpp b/src/effects/SkArithmeticImageFilter.cpp
index faf94ef..cf85cfa 100644
--- a/src/effects/SkArithmeticImageFilter.cpp
+++ b/src/effects/SkArithmeticImageFilter.cpp
@@ -28,7 +28,6 @@
 #include "glsl/GrGLSLUniformHandler.h"
 #endif
 
-namespace {
 class ArithmeticImageFilterImpl : public SkImageFilter {
 public:
     ArithmeticImageFilterImpl(float k1, float k2, float k3, float k4, bool enforcePMColor,
@@ -62,6 +61,8 @@
 
     void drawForeground(SkCanvas* canvas, SkSpecialImage*, const SkIRect&) const;
 
+    sk_sp<SkImageFilter> onMakeColorSpace(SkColorSpaceXformer*) const override;
+
 private:
     const float fK[4];
     const bool fEnforcePMColor;
@@ -70,7 +71,6 @@
 
     typedef SkImageFilter INHERITED;
 };
-}
 
 sk_sp<SkFlattenable> ArithmeticImageFilterImpl::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 2);
@@ -457,6 +457,22 @@
     }
 }
 
+sk_sp<SkImageFilter> ArithmeticImageFilterImpl::onMakeColorSpace(SkColorSpaceXformer* xformer)
+const {
+    SkASSERT(2 == this->countInputs());
+    if (!this->getInput(0) && !this->getInput(1)) {
+        return sk_ref_sp(const_cast<ArithmeticImageFilterImpl*>(this));
+    }
+
+    sk_sp<SkImageFilter> background =
+            this->getInput(0) ? this->getInput(0)->makeColorSpace(xformer) : nullptr;
+    sk_sp<SkImageFilter> foreground =
+            this->getInput(1) ? this->getInput(1)->makeColorSpace(xformer) : nullptr;
+    return SkArithmeticImageFilter::Make(fK[0], fK[1], fK[2], fK[3], fEnforcePMColor,
+                                         std::move(background), std::move(foreground),
+                                         getCropRectIfSet());
+}
+
 #ifndef SK_IGNORE_TO_STRING
 void ArithmeticImageFilterImpl::toString(SkString* str) const {
     str->appendf("SkArithmeticImageFilter: (");
diff --git a/src/effects/SkPaintImageFilter.cpp b/src/effects/SkPaintImageFilter.cpp
index 0a0e4e9..c793858 100644
--- a/src/effects/SkPaintImageFilter.cpp
+++ b/src/effects/SkPaintImageFilter.cpp
@@ -7,6 +7,7 @@
 
 #include "SkPaintImageFilter.h"
 #include "SkCanvas.h"
+#include "SkColorSpaceXformer.h"
 #include "SkReadBuffer.h"
 #include "SkSpecialImage.h"
 #include "SkSpecialSurface.h"
@@ -68,6 +69,10 @@
     return surf->makeImageSnapshot();
 }
 
+sk_sp<SkImageFilter> SkPaintImageFilter::onMakeColorSpace(SkColorSpaceXformer* xformer) const {
+    return SkPaintImageFilter::Make(xformer->apply(fPaint), this->getCropRectIfSet());
+}
+
 bool SkPaintImageFilter::affectsTransparentBlack() const {
     return true;
 }