Revert of Add gpu implementation of OverdrawXfermode (patchset #6 id:100001 of https://codereview.chromium.org/1607253002/ )

Reason for revert:
Overdraw Xfer mode using new fangled glsl features

Original issue's description:
> Add gpu implementation of OverdrawXfermode
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1607253002
>
> Committed: https://skia.googlesource.com/skia/+/8bc3cf88bbf5e5d5724356f076931bb70a6117ba

TBR=egdaniel@google.com
# Not skipping CQ checks because original CL landed more than 1 days ago.

Review URL: https://codereview.chromium.org/1626443002
diff --git a/debugger/QT/SkDebuggerGUI.cpp b/debugger/QT/SkDebuggerGUI.cpp
index 0c369f6..0d009b3 100644
--- a/debugger/QT/SkDebuggerGUI.cpp
+++ b/debugger/QT/SkDebuggerGUI.cpp
@@ -202,6 +202,7 @@
 void SkDebuggerGUI::actionRasterSettingsChanged() {
     fCanvasWidget.setWidgetVisibility(SkCanvasWidget::kRaster_8888_WidgetType,
                                       !fSettingsWidget.isRasterEnabled());
+    fDebugger.setOverdrawViz(fSettingsWidget.isOverdrawVizEnabled());
     this->updateImage();
 }
 
@@ -209,7 +210,6 @@
     fDebugger.setMegaViz(fSettingsWidget.isMegaVizEnabled());
     fDebugger.setPathOps(fSettingsWidget.isPathOpsEnabled());
     fDebugger.highlightCurrentCommand(fSettingsWidget.isVisibilityFilterEnabled());
-    fDebugger.setOverdrawViz(fSettingsWidget.isOverdrawVizEnabled());
     this->updateImage();
 }
 
diff --git a/debugger/QT/SkSettingsWidget.cpp b/debugger/QT/SkSettingsWidget.cpp
index 4665217..59b7920 100644
--- a/debugger/QT/SkSettingsWidget.cpp
+++ b/debugger/QT/SkSettingsWidget.cpp
@@ -21,36 +21,30 @@
 
     // Visualizations toggles.
     fVisualizationsGroup.setTitle("Visualizations");
-
     fVisibilityFilterCheckBox.setText("Visibility Filter");
     fVisualizationsLayout.addWidget(&fVisibilityFilterCheckBox);
-
     fMegaVizCheckBox.setText("Mega Viz");
     fVisualizationsLayout.addWidget(&fMegaVizCheckBox);
-
     fPathOpsCheckBox.setText("PathOps ");
     fVisualizationsLayout.addWidget(&fPathOpsCheckBox);
-
-    fOverdrawVizCheckBox.setText("Overdraw Viz");
-    fVisualizationsLayout.addWidget(&fOverdrawVizCheckBox);
-
     fVisualizationsGroup.setLayout(&fVisualizationsLayout);
-
     connect(&fVisibilityFilterCheckBox, SIGNAL(toggled(bool)), this,
             SIGNAL(visualizationsChanged()));
     connect(&fMegaVizCheckBox, SIGNAL(toggled(bool)), this, SIGNAL(visualizationsChanged()));
     connect(&fPathOpsCheckBox, SIGNAL(toggled(bool)), this, SIGNAL(visualizationsChanged()));
-    connect(&fOverdrawVizCheckBox, SIGNAL(toggled(bool)), this, SIGNAL(visualizationsChanged()));
 
     fVerticalLayout.addRow(&fVisualizationsGroup);
 
     // Raster toggles.
     fRasterGroup.setTitle("Raster");
     fRasterGroup.setCheckable(true);
+    fOverdrawVizCheckBox.setText("Overdraw Viz");
+    fRasterLayout.addWidget(&fOverdrawVizCheckBox);
     fRasterGroup.setLayout(&fRasterLayout);
     fVerticalLayout.addRow(&fRasterGroup);
 
     connect(&fRasterGroup, SIGNAL(toggled(bool)), this, SIGNAL(rasterSettingsChanged()));
+    connect(&fOverdrawVizCheckBox, SIGNAL(toggled(bool)), this, SIGNAL(rasterSettingsChanged()));
 
 #if SK_SUPPORT_GPU
     fGLGroup.setTitle("OpenGL");
diff --git a/gyp/debugger.gyp b/gyp/debugger.gyp
index fb02696..6cc2a40 100644
--- a/gyp/debugger.gyp
+++ b/gyp/debugger.gyp
@@ -101,8 +101,6 @@
         '../src/utils/debugger/SkDrawCommand.cpp',
         '../src/utils/debugger/SkObjectParser.h',
         '../src/utils/debugger/SkObjectParser.cpp',
-        '../src/utils/debugger/SkOverdrawMode.h',
-        '../src/utils/debugger/SkOverdrawMode.cpp',
         '../debugger/debuggermain.cpp',
         '../debugger/QT/SkDebuggerGUI.cpp',
         '../debugger/QT/SkDebuggerGUI.h',
diff --git a/gyp/dm.gypi b/gyp/dm.gypi
index bb21923..8ad3e68 100644
--- a/gyp/dm.gypi
+++ b/gyp/dm.gypi
@@ -44,8 +44,6 @@
     '../src/utils/debugger/SkDebugCanvas.cpp',
     '../src/utils/debugger/SkDrawCommand.cpp',
     '../src/utils/debugger/SkObjectParser.cpp',
-    '../src/utils/debugger/SkOverdrawMode.h',
-    '../src/utils/debugger/SkOverdrawMode.cpp',
   ],
   'conditions': [
     [ 'skia_gpu == 1', {
diff --git a/gyp/gmslides.gypi b/gyp/gmslides.gypi
index cf5d162..87910e5 100644
--- a/gyp/gmslides.gypi
+++ b/gyp/gmslides.gypi
@@ -27,8 +27,6 @@
         '../src/utils/debugger/SkDebugCanvas.cpp',
         '../src/utils/debugger/SkObjectParser.h',
         '../src/utils/debugger/SkObjectParser.cpp',
-        '../src/utils/debugger/SkOverdrawMode.h',
-        '../src/utils/debugger/SkOverdrawMode.cpp',
       ],
     }],
   ],
diff --git a/gyp/tests.gypi b/gyp/tests.gypi
index 5f3df96..10bfdb4 100644
--- a/gyp/tests.gypi
+++ b/gyp/tests.gypi
@@ -57,8 +57,6 @@
     '../src/utils/debugger/SkDebugCanvas.cpp',
     '../src/utils/debugger/SkObjectParser.h',
     '../src/utils/debugger/SkObjectParser.cpp',
-    '../src/utils/debugger/SkOverdrawMode.h',
-    '../src/utils/debugger/SkOverdrawMode.cpp',
   ],
   'sources!': [
     '../tests/SkpSkGrTest.cpp',
diff --git a/src/effects/SkArithmeticMode.cpp b/src/effects/SkArithmeticMode.cpp
index 2e68cab..9eb7dd2 100644
--- a/src/effects/SkArithmeticMode.cpp
+++ b/src/effects/SkArithmeticMode.cpp
@@ -21,13 +21,13 @@
 
 class SkArithmeticMode_scalar : public SkXfermode {
 public:
-    static SkXfermode* Create(SkScalar k1, SkScalar k2, SkScalar k3, SkScalar k4,
-                              bool enforcePMColor) {
+    static SkArithmeticMode_scalar* Create(SkScalar k1, SkScalar k2, SkScalar k3, SkScalar k4,
+                                           bool enforcePMColor) {
         return new SkArithmeticMode_scalar(k1, k2, k3, k4, enforcePMColor);
     }
 
-    void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
-                const SkAlpha aa[]) const override;
+    virtual void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
+                        const SkAlpha aa[]) const override;
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkArithmeticMode_scalar)
diff --git a/src/effects/SkArithmeticMode_gpu.cpp b/src/effects/SkArithmeticMode_gpu.cpp
index 29c6602..ce8e426 100644
--- a/src/effects/SkArithmeticMode_gpu.cpp
+++ b/src/effects/SkArithmeticMode_gpu.cpp
@@ -226,8 +226,17 @@
         add_arithmetic_code(fragBuilder, srcColor, dstColor, outColor, kUni, fEnforcePMColor);
 
         // Apply coverage.
-        INHERITED::DefaultCoverageModulation(fragBuilder, srcCoverage, dstColor, outColor,
-                                             outColorSecondary, proc);
+        if (proc.dstReadUsesMixedSamples()) {
+            if (srcCoverage) {
+                fragBuilder->codeAppendf("%s *= %s;", outColor, srcCoverage);
+                fragBuilder->codeAppendf("%s = %s;", outColorSecondary, srcCoverage);
+            } else {
+                fragBuilder->codeAppendf("%s = vec4(1.0);", outColorSecondary);
+            }
+        } else if (srcCoverage) {
+            fragBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;",
+                                     outColor, srcCoverage, outColor, srcCoverage, dstColor);
+        }
     }
 
     void onSetData(const GrGLSLProgramDataManager& pdman,
diff --git a/src/gpu/GrProcessor.cpp b/src/gpu/GrProcessor.cpp
index 20f7d72..1db9d76 100644
--- a/src/gpu/GrProcessor.cpp
+++ b/src/gpu/GrProcessor.cpp
@@ -48,9 +48,9 @@
  * we verify the count is as expected.  If a new factory is added, then these numbers must be
  * manually adjusted.
  */
-static const int kFPFactoryCount = 39;
+static const int kFPFactoryCount = 38;
 static const int kGPFactoryCount = 14;
-static const int kXPFactoryCount = 6;
+static const int kXPFactoryCount = 5;
 
 template<>
 void GrProcessorTestFactory<GrFragmentProcessor>::VerifyFactoryCount() {
diff --git a/src/gpu/effects/GrCustomXfermode.cpp b/src/gpu/effects/GrCustomXfermode.cpp
index dccec0c..93f2073 100644
--- a/src/gpu/effects/GrCustomXfermode.cpp
+++ b/src/gpu/effects/GrCustomXfermode.cpp
@@ -175,8 +175,17 @@
         GrGLSLBlend::AppendMode(fragBuilder, srcColor, dstColor, outColor, xp.mode());
 
         // Apply coverage.
-        INHERITED::DefaultCoverageModulation(fragBuilder, srcCoverage, dstColor, outColor,
-                                             outColorSecondary, xp);
+        if (xp.dstReadUsesMixedSamples()) {
+            if (srcCoverage) {
+                fragBuilder->codeAppendf("%s *= %s;", outColor, srcCoverage);
+                fragBuilder->codeAppendf("%s = %s;", outColorSecondary, srcCoverage);
+            } else {
+                fragBuilder->codeAppendf("%s = vec4(1.0);", outColorSecondary);
+            }
+        } else if (srcCoverage) {
+            fragBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;",
+                                     outColor, srcCoverage, outColor, srcCoverage, dstColor);
+        }
     }
 
     void onSetData(const GrGLSLProgramDataManager&, const GrXferProcessor&) override {}
diff --git a/src/gpu/effects/GrPorterDuffXferProcessor.cpp b/src/gpu/effects/GrPorterDuffXferProcessor.cpp
index d1059c7..2ea45a5 100644
--- a/src/gpu/effects/GrPorterDuffXferProcessor.cpp
+++ b/src/gpu/effects/GrPorterDuffXferProcessor.cpp
@@ -559,8 +559,17 @@
         GrGLSLBlend::AppendMode(fragBuilder, srcColor, dstColor, outColor, xp.getXfermode());
 
         // Apply coverage.
-        INHERITED::DefaultCoverageModulation(fragBuilder, srcCoverage, dstColor, outColor,
-                                             outColorSecondary, xp);
+        if (xp.dstReadUsesMixedSamples()) {
+            if (srcCoverage) {
+                fragBuilder->codeAppendf("%s *= %s;", outColor, srcCoverage);
+                fragBuilder->codeAppendf("%s = %s;", outColorSecondary, srcCoverage);
+            } else {
+                fragBuilder->codeAppendf("%s = vec4(1.0);", outColorSecondary);
+            }
+        } else if (srcCoverage) {
+            fragBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;",
+                                     outColor, srcCoverage, outColor, srcCoverage, dstColor);
+        }
     }
 
     void onSetData(const GrGLSLProgramDataManager&, const GrXferProcessor&) override {}
diff --git a/src/gpu/glsl/GrGLSLXferProcessor.cpp b/src/gpu/glsl/GrGLSLXferProcessor.cpp
index 9d2538f..81bd015 100644
--- a/src/gpu/glsl/GrGLSLXferProcessor.cpp
+++ b/src/gpu/glsl/GrGLSLXferProcessor.cpp
@@ -88,21 +88,3 @@
     this->onSetData(pdm, xp);
 }
 
-void GrGLSLXferProcessor::DefaultCoverageModulation(GrGLSLXPFragmentBuilder* fragBuilder,
-                                                    const char* srcCoverage,
-                                                    const char* dstColor,
-                                                    const char* outColor,
-                                                    const char* outColorSecondary,
-                                                    const GrXferProcessor& proc) {
-    if (proc.dstReadUsesMixedSamples()) {
-        if (srcCoverage) {
-            fragBuilder->codeAppendf("%s *= %s;", outColor, srcCoverage);
-            fragBuilder->codeAppendf("%s = %s;", outColorSecondary, srcCoverage);
-        } else {
-            fragBuilder->codeAppendf("%s = vec4(1.0);", outColorSecondary);
-        }
-    } else if (srcCoverage) {
-        fragBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;",
-                                 outColor, srcCoverage, outColor, srcCoverage, dstColor);
-    }
-}
diff --git a/src/gpu/glsl/GrGLSLXferProcessor.h b/src/gpu/glsl/GrGLSLXferProcessor.h
index 478956d..1a997a5 100644
--- a/src/gpu/glsl/GrGLSLXferProcessor.h
+++ b/src/gpu/glsl/GrGLSLXferProcessor.h
@@ -71,14 +71,6 @@
      */
     void setData(const GrGLSLProgramDataManager& pdm, const GrXferProcessor& xp);
 
-protected:
-    static void DefaultCoverageModulation(GrGLSLXPFragmentBuilder* fragBuilder,
-                                          const char* srcCoverage,
-                                          const char* dstColor,
-                                          const char* outColor,
-                                          const char* outColorSecondary,
-                                          const GrXferProcessor& proc);
-
 private:
     /**
      * Called by emitCode() when the XP will not be performing a dst read. This method is
diff --git a/src/utils/debugger/SkDebugCanvas.cpp b/src/utils/debugger/SkDebugCanvas.cpp
index c2dd8f8..63739ae 100644
--- a/src/utils/debugger/SkDebugCanvas.cpp
+++ b/src/utils/debugger/SkDebugCanvas.cpp
@@ -6,11 +6,55 @@
  */
 
 #include "SkClipStack.h"
+#include "SkColorPriv.h"
 #include "SkDebugCanvas.h"
 #include "SkDrawCommand.h"
 #include "SkDevice.h"
 #include "SkPaintFilterCanvas.h"
-#include "SkOverdrawMode.h"
+#include "SkXfermode.h"
+
+namespace {
+
+class OverdrawXfermode : public SkXfermode {
+public:
+    SkPMColor xferColor(SkPMColor src, SkPMColor dst) const override {
+        // This table encodes the color progression of the overdraw visualization
+        static const SkPMColor gTable[] = {
+            SkPackARGB32(0x00, 0x00, 0x00, 0x00),
+            SkPackARGB32(0xFF, 128, 158, 255),
+            SkPackARGB32(0xFF, 170, 185, 212),
+            SkPackARGB32(0xFF, 213, 195, 170),
+            SkPackARGB32(0xFF, 255, 192, 127),
+            SkPackARGB32(0xFF, 255, 185, 85),
+            SkPackARGB32(0xFF, 255, 165, 42),
+            SkPackARGB32(0xFF, 255, 135, 0),
+            SkPackARGB32(0xFF, 255,  95, 0),
+            SkPackARGB32(0xFF, 255,  50, 0),
+            SkPackARGB32(0xFF, 255,  0, 0)
+        };
+
+
+        int idx;
+        if (SkColorGetR(dst) < 64) { // 0
+            idx = 0;
+        } else if (SkColorGetG(dst) < 25) { // 10
+            idx = 9;  // cap at 9 for upcoming increment
+        } else if ((SkColorGetB(dst)+21)/42 > 0) { // 1-6
+            idx = 7 - (SkColorGetB(dst)+21)/42;
+        } else { // 7-9
+            idx = 10 - (SkColorGetG(dst)+22)/45;
+        }
+        ++idx;
+        SkASSERT(idx < (int)SK_ARRAY_COUNT(gTable));
+
+        return gTable[idx];
+    }
+
+    Factory getFactory() const override { return nullptr; }
+#ifndef SK_IGNORE_TO_STRING
+    void toString(SkString* str) const override { str->set("OverdrawXfermode"); }
+#endif
+};
 
 class DebugPaintFilterCanvas : public SkPaintFilterCanvas {
 public:
@@ -20,7 +64,7 @@
                            bool overrideFilterQuality,
                            SkFilterQuality quality)
         : INHERITED(width, height)
-        , fOverdrawXfermode(overdrawViz ? SkOverdrawMode::Create() : nullptr)
+        , fOverdrawXfermode(overdrawViz ? new OverdrawXfermode : nullptr)
         , fOverrideFilterQuality(overrideFilterQuality)
         , fFilterQuality(quality) {}
 
@@ -55,6 +99,8 @@
     typedef SkPaintFilterCanvas INHERITED;
 };
 
+}
+
 SkDebugCanvas::SkDebugCanvas(int width, int height)
         : INHERITED(width, height)
         , fPicture(nullptr)
diff --git a/src/utils/debugger/SkOverdrawMode.cpp b/src/utils/debugger/SkOverdrawMode.cpp
deleted file mode 100644
index 72001ec..0000000
--- a/src/utils/debugger/SkOverdrawMode.cpp
+++ /dev/null
@@ -1,323 +0,0 @@
-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkColorPriv.h"
-#include "SkOverdrawMode.h"
-#include "SkString.h"
-#include "SkXfermode.h"
-
-#if SK_SUPPORT_GPU
-#include "GrFragmentProcessor.h"
-#include "GrInvariantOutput.h"
-#include "GrXferProcessor.h"
-#include "glsl/GrGLSLFragmentProcessor.h"
-#include "glsl/GrGLSLFragmentShaderBuilder.h"
-#include "glsl/GrGLSLXferProcessor.h"
-
- ///////////////////////////////////////////////////////////////////////////////
- // Fragment Processor
- ///////////////////////////////////////////////////////////////////////////////
-
-class GLOverdrawFP;
-
-class GrOverdrawFP : public GrFragmentProcessor {
-public:
-    static const GrFragmentProcessor* Create(const GrFragmentProcessor* dst) {
-        return new GrOverdrawFP(dst);
-    }
-
-    ~GrOverdrawFP() override { }
-
-    const char* name() const override { return "Overdraw"; }
-
-    SkString dumpInfo() const override {
-        SkString str;
-        return str;
-    }
-
-private:
-    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
-
-    void onGetGLSLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder* b) const override;
-
-    bool onIsEqual(const GrFragmentProcessor&) const override { return true; }
-
-    void onComputeInvariantOutput(GrInvariantOutput* inout) const override {
-        inout->setToUnknown(GrInvariantOutput::kWill_ReadInput);
-    }
-
-    GrOverdrawFP(const GrFragmentProcessor* dst) {
-        this->initClassID<GrOverdrawFP>();
-
-        SkASSERT(dst);
-        SkDEBUGCODE(int dstIndex = )this->registerChildProcessor(dst);
-        SkASSERT(0 == dstIndex);
-    }
-
-    GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
-    typedef GrFragmentProcessor INHERITED;
-};
-
-///////////////////////////////////////////////////////////////////////////////
-
-static void add_overdraw_code(GrGLSLFragmentBuilder* fragBuilder,
-                              const char* dstColor,
-                              const char* outputColor) {
-
-    fragBuilder->codeAppend("vec4 gTable[11] = vec4[11](");
-    fragBuilder->codeAppend("vec4(0,     0,     0,     0.0),");
-    fragBuilder->codeAppend("vec4(0.5,   0.617, 1.0,   1.0),");
-    fragBuilder->codeAppend("vec4(0.664, 0.723, 0.83,  1.0),");
-    fragBuilder->codeAppend("vec4(0.832, 0.762, 0.664, 1.0),");
-    fragBuilder->codeAppend("vec4(1,     0.75,  0.496, 1.0),");
-    fragBuilder->codeAppend("vec4(1,     0.723, 0.332, 1.0),");
-    fragBuilder->codeAppend("vec4(1,     0.645, 0.164, 1.0),");
-    fragBuilder->codeAppend("vec4(1,     0.527, 0,     1.0),");
-    fragBuilder->codeAppend("vec4(1,     0.371, 0,     1.0),");
-    fragBuilder->codeAppend("vec4(1,     0.195, 0,     1.0),");
-    fragBuilder->codeAppend("vec4(1,     0,     0,     1.0)");
-    fragBuilder->codeAppend(");");
-
-    fragBuilder->codeAppend("int nextIdx;");
-    fragBuilder->codeAppendf("vec4 dst = %s;", dstColor);
-    fragBuilder->codeAppend("if (dst.r < 0.25) { nextIdx = 1; }");
-    // cap 'idx' at 10
-    fragBuilder->codeAppend("else if (dst.g < 0.0977) { nextIdx = 10; }");
-    fragBuilder->codeAppend("else if (dst.b > 0.08) { nextIdx = 8 - int(6 * dst.b + 0.5); }");
-    fragBuilder->codeAppend("else { nextIdx = 11 - int(5.7 * dst.g + 0.5); }");
-    fragBuilder->codeAppendf("%s = gTable[nextIdx];", outputColor);
-}
-
-class GLOverdrawFP : public GrGLSLFragmentProcessor {
-public:
-    GLOverdrawFP(const GrOverdrawFP&) {}
-
-    ~GLOverdrawFP() override {}
-
-    void emitCode(EmitArgs& args) override {
-        GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
-        SkString dstColor("dstColor");
-        this->emitChild(0, nullptr, &dstColor, args);
-
-        add_overdraw_code(fragBuilder, dstColor.c_str(), args.fOutputColor);
-    }
-
-    static void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*) { }
-
-private:
-    typedef GrGLSLFragmentProcessor INHERITED;
-};
-
-///////////////////////////////////////////////////////////////////////////////
-
-GrGLSLFragmentProcessor* GrOverdrawFP::onCreateGLSLInstance() const {
-    return new GLOverdrawFP(*this);
-}
-
-void GrOverdrawFP::onGetGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const {
-    GLOverdrawFP::GenKey(*this, caps, b);
-}
-
-const GrFragmentProcessor* GrOverdrawFP::TestCreate(GrProcessorTestData* d) {
-    SkAutoTUnref<const GrFragmentProcessor> dst(GrProcessorUnitTest::CreateChildFP(d));
-    return new GrOverdrawFP(dst);
-}
-
-GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrOverdrawFP);
-
-///////////////////////////////////////////////////////////////////////////////
-// Xfer Processor
-///////////////////////////////////////////////////////////////////////////////
-
-class OverdrawXP : public GrXferProcessor {
-public:
-    OverdrawXP(const DstTexture* dstTexture, bool hasMixedSamples)
-        : INHERITED(dstTexture, true, hasMixedSamples) {
-        this->initClassID<OverdrawXP>();
-    }
-
-    const char* name() const override { return "Overdraw"; }
-
-    GrGLSLXferProcessor* createGLSLInstance() const override;
-
-private:
-    GrXferProcessor::OptFlags onGetOptimizations(const GrPipelineOptimizations& optimizations,
-                                                 bool doesStencilWrite,
-                                                 GrColor* overrideColor,
-                                                 const GrCaps& caps) const override {
-        // We never look at the color input
-        return GrXferProcessor::kIgnoreColor_OptFlag;
-    }
-
-    void onGetGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override;
-
-    bool onIsEqual(const GrXferProcessor&) const override { return true; }
-
-    typedef GrXferProcessor INHERITED;
-};
-
-///////////////////////////////////////////////////////////////////////////////
-
-class GLOverdrawXP : public GrGLSLXferProcessor {
-public:
-    GLOverdrawXP(const OverdrawXP&) { }
-
-    ~GLOverdrawXP() override {}
-
-    static void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*) { }
-
-private:
-    void emitBlendCodeForDstRead(GrGLSLXPFragmentBuilder* fragBuilder,
-                                 GrGLSLUniformHandler* uniformHandler,
-                                 const char* srcColor,
-                                 const char* srcCoverage,
-                                 const char* dstColor,
-                                 const char* outColor,
-                                 const char* outColorSecondary,
-                                 const GrXferProcessor& proc) override {
-        add_overdraw_code(fragBuilder, dstColor, outColor);
-
-        // Apply coverage.
-        INHERITED::DefaultCoverageModulation(fragBuilder, srcCoverage, dstColor, outColor,
-                                             outColorSecondary, proc);
-    }
-
-    void onSetData(const GrGLSLProgramDataManager&, const GrXferProcessor&) override { };
-
-    typedef GrGLSLXferProcessor INHERITED;
-};
-
-///////////////////////////////////////////////////////////////////////////////
-
-void OverdrawXP::onGetGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const {
-    GLOverdrawXP::GenKey(*this, caps, b);
-}
-
-GrGLSLXferProcessor* OverdrawXP::createGLSLInstance() const { return new GLOverdrawXP(*this); }
-
-///////////////////////////////////////////////////////////////////////////////
-class GrOverdrawXPFactory : public GrXPFactory {
-public:
-    static GrXPFactory* Create() { return new GrOverdrawXPFactory(); }
-
-    void getInvariantBlendedColor(const GrProcOptInfo& colorPOI,
-                                  GrXPFactory::InvariantBlendedColor* blendedColor) const override {
-        blendedColor->fWillBlendWithDst = true;
-        blendedColor->fKnownColorFlags = kNone_GrColorComponentFlags;
-    }
-
-private:
-    GrOverdrawXPFactory() {
-        this->initClassID<GrOverdrawXPFactory>();
-    }
-
-    GrXferProcessor* onCreateXferProcessor(const GrCaps& caps,
-                                           const GrPipelineOptimizations& optimizations,
-                                           bool hasMixedSamples,
-                                           const DstTexture* dstTexture) const override {
-        return new OverdrawXP(dstTexture, hasMixedSamples);
-    }
-
-    bool onWillReadDstColor(const GrCaps& caps,
-                            const GrPipelineOptimizations& optimizations,
-                            bool hasMixedSamples) const override {
-        return true;
-    }
-
-    bool onIsEqual(const GrXPFactory& xpfBase) const override { return true; }
-
-    GR_DECLARE_XP_FACTORY_TEST;
-
-    typedef GrXPFactory INHERITED;
-};
-
-GR_DEFINE_XP_FACTORY_TEST(GrOverdrawXPFactory);
-
-const GrXPFactory* GrOverdrawXPFactory::TestCreate(GrProcessorTestData* d) {
-    return GrOverdrawXPFactory::Create();
-}
-#endif
-
-///////////////////////////////////////////////////////////////////////////////
-class SkOverdrawXfermode : public SkXfermode {
-public:
-    static SkXfermode* Create() {
-        return new SkOverdrawXfermode;
-    }
-
-    SkPMColor xferColor(SkPMColor src, SkPMColor dst) const override {
-        // This table encodes the color progression of the overdraw visualization
-        static const SkPMColor gTable[] = {
-            SkPackARGB32(0x00, 0x00, 0x00, 0x00),
-            SkPackARGB32(0xFF, 128, 158, 255),
-            SkPackARGB32(0xFF, 170, 185, 212),
-            SkPackARGB32(0xFF, 213, 195, 170),
-            SkPackARGB32(0xFF, 255, 192, 127),
-            SkPackARGB32(0xFF, 255, 185, 85),
-            SkPackARGB32(0xFF, 255, 165, 42),
-            SkPackARGB32(0xFF, 255, 135, 0),
-            SkPackARGB32(0xFF, 255,  95, 0),
-            SkPackARGB32(0xFF, 255,  50, 0),
-            SkPackARGB32(0xFF, 255,  0, 0)
-        };
-
-
-        int nextIdx;
-        if (SkColorGetR(dst) < 64) { // dst color is the 0th color so the next color is 1
-            nextIdx = 1;
-        } else if (SkColorGetG(dst) < 25) { // dst color is the 10th color so cap there
-            nextIdx = 10;
-        } else if ((SkColorGetB(dst)+21)/42 > 0) { // dst color is one of 1-6
-            nextIdx = 8 - (SkColorGetB(dst)+21)/42;
-        } else { // dst color is between 7 and 9
-            nextIdx = 11 - (SkColorGetG(dst)+22)/45;
-        }
-        SkASSERT(nextIdx < (int)SK_ARRAY_COUNT(gTable));
-
-        return gTable[nextIdx];
-    }
-
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkOverdrawXfermode)
-
-#if SK_SUPPORT_GPU
-    bool asFragmentProcessor(const GrFragmentProcessor** output,
-                             const GrFragmentProcessor* dst) const override {
-        if (output) {
-            *output = GrOverdrawFP::Create(dst);
-        }
-        return true;
-    }
-
-    bool asXPFactory(GrXPFactory** xpf) const override {
-        if (xpf) {
-            *xpf = GrOverdrawXPFactory::Create();
-        }
-        return true;
-    }
-#endif
-
-#ifndef SK_IGNORE_TO_STRING
-    void toString(SkString* str) const override { str->set("SkOverdrawXfermode"); }
-#endif
-
-private:
-    friend class SkOverdrawMode;
-
-    void flatten(SkWriteBuffer& buffer) const override { }
-
-    typedef SkXfermode INHERITED;
-};
-
-SkFlattenable* SkOverdrawXfermode::CreateProc(SkReadBuffer& buffer) {
-    return Create();
-}
-
-SkXfermode* SkOverdrawMode::Create() { return new SkOverdrawXfermode; }
-
-SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkOverdrawMode)
-    SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkOverdrawXfermode)
-SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END
diff --git a/src/utils/debugger/SkOverdrawMode.h b/src/utils/debugger/SkOverdrawMode.h
deleted file mode 100644
index dba7635..0000000
--- a/src/utils/debugger/SkOverdrawMode.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkOverdrawMode_DEFINED
-#define SkOverdrawMode_DEFINED
-
-#include "SkFlattenable.h"
-
-class SkXfermode;
-
-class SkOverdrawMode {
-public:
-    static SkXfermode* Create();
-
-    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP();
-
-private:
-    SkOverdrawMode(); // can't be instantiated
-};
-
-#endif