Revert of Implement canComputeFastBounds() for image filters. (patchset #8 id:130001 of https://codereview.chromium.org/1296943002/ )

Reason for revert:
This causes a syntax error.

http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_compile_dbg_ng/builds/87819/steps/compile%20%28with%20patch%29/logs/stdio

Original issue's description:
> Implement canComputeFastBounds() for image filters.
>
> Image filters have never implemented this check, which means that
> filters which affect transparent black falsely claim they can compute
> their bounds.
>
> Implemented an affectsTransparentBlack() virtual for image
> filters, and a similar helper function for color filters.
>
> This will affect the following GMs: imagefiltersscaled
> (lighting, perlin noise now filter to clip),
> colorfilterimagefilter (new test case), imagefiltersclipped
> (perlin noise now filters to clip).
>
> Note: I de-inlined SkPaint::canComputeFastBounds() to avoid adding
> a dependency from SkPaint.h to SkImageFilter.h.h. Skia benches show
> no impact from this change, but will watch the perf bots carefully.
>
> BUG=4212
>
> Committed: https://skia.googlesource.com/skia/+/915881fe743f9a789037695f543bc6ea189cd0cb

TBR=reed@google.com,senorblanco@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=4212

Review URL: https://codereview.chromium.org/1300403003

gm/colorfilterimagefilter.cpp

@@ -45,7 +45,7 @@ static SkImageFilter* make_grayscale(SkImageFilter* input = NULL) {
 
 static SkImageFilter* make_mode_blue(SkImageFilter* input = NULL) {
     SkAutoTUnref<SkColorFilter> filter(
-        SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrc_Mode));
+        SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrcIn_Mode));
     return SkColorFilterImageFilter::Create(filter, input);
 }
 
@@ -120,12 +120,6 @@ protected:
             drawClippedRect(canvas, r, paint, 3);
             canvas->translate(FILTER_WIDTH + MARGIN, 0);
         }
-        {
-            SkAutoTUnref<SkImageFilter> blue(make_mode_blue());
-            paint.setImageFilter(blue.get());
-            drawClippedRect(canvas, r, paint, 5);
-            canvas->translate(FILTER_WIDTH + MARGIN, 0);
-        }
     }
 
 private:

gm/imagefiltersscaled.cpp

@@ -131,7 +131,6 @@ protected:
                 paint.setAntiAlias(true);
                 canvas->save();
                 canvas->scale(scales[j].fX, scales[j].fY);
-                canvas->clipRect(r);
                 if (5 == i) {
                     canvas->translate(SkIntToScalar(-32), 0);
                 } else if (6 == i) {

include/core/SkColorFilter.h

@@ -140,10 +140,6 @@ public:
         return false;
     }
 
-    bool affectsTransparentBlack() const {
-        return this->filterColor(0) != 0;
-    }
-
     SK_TO_STRING_PUREVIRT()
 
     SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()

include/core/SkImageFilter.h

@@ -178,7 +178,6 @@ public:
     bool asAColorFilter(SkColorFilter** filterPtr) const {
         return this->countInputs() > 0 &&
                NULL == this->getInput(0) &&
-               !this->affectsTransparentBlack() &&
                this->isColorFilterNode(filterPtr);
     }
 
@@ -215,9 +214,6 @@ public:
     // Default impl returns union of all input bounds.
     virtual void computeFastBounds(const SkRect&, SkRect*) const;
 
-    // Can this filter DAG compute the resulting bounds of an object-space rectangle?
-    bool canComputeFastBounds() const;
-
     /**
      * Create an SkMatrixImageFilter, which transforms its input by the given matrix.
      */
@@ -366,14 +362,6 @@ protected:
     virtual bool asFragmentProcessor(GrFragmentProcessor**, GrProcessorDataManager*, GrTexture*,
                                      const SkMatrix&, const SkIRect& bounds) const;
 
-    /**
-     * Returns true if this filter can cause transparent black pixels to become
-     * visible (ie., alpha > 0). The default implementation returns false. This
-     * function is non-recursive, i.e., only queries this filter and not its
-     * inputs.
-     */
-    virtual bool affectsTransparentBlack() const;
-
 private:
     friend class SkGraphics;
     static void PurgeCache();

include/core/SkPaint.h

@@ -9,6 +9,7 @@
 #define SkPaint_DEFINED
 
 #include "SkColor.h"
+#include "SkDrawLooper.h"
 #include "SkFilterQuality.h"
 #include "SkMatrix.h"
 #include "SkXfermode.h"
@@ -19,7 +20,6 @@ class SkAutoGlyphCache;
 class SkColorFilter;
 class SkData;
 class SkDescriptor;
-class SkDrawLooper;
 class SkReadBuffer;
 class SkWriteBuffer;
 class SkGlyph;
@@ -909,7 +909,12 @@ public:
      bounds (i.e. there is nothing complex like a patheffect that would make
      the bounds computation expensive.
      */
-    bool canComputeFastBounds() const;
+    bool canComputeFastBounds() const {
+        if (this->getLooper()) {
+            return this->getLooper()->canComputeFastBounds(*this);
+        }
+        return !this->getRasterizer();
+    }
 
     /** Only call this if canComputeFastBounds() returned true. This takes a
      raw rectangle (the raw bounds of a shape), and adjusts it for stylistic

include/effects/SkColorFilterImageFilter.h

@@ -29,7 +29,6 @@ protected:
                                SkBitmap* result, SkIPoint* loc) const override;
 
     bool onIsColorFilterNode(SkColorFilter**) const override;
-    bool affectsTransparentBlack() const override;
 
 private:
     SkColorFilterImageFilter(SkColorFilter* cf,

include/effects/SkLightingImageFilter.h

@@ -49,7 +49,6 @@ protected:
     void flatten(SkWriteBuffer&) const override;
     const SkImageFilterLight* light() const { return fLight.get(); }
     SkScalar surfaceScale() const { return fSurfaceScale; }
-    bool affectsTransparentBlack() const override { return true; }
 
 private:
     typedef SkImageFilter INHERITED;

include/effects/SkRectShaderImageFilter.h

@@ -30,7 +30,6 @@ public:
 
     static SkRectShaderImageFilter* Create(SkShader* s, const CropRect* rect = NULL);
     virtual ~SkRectShaderImageFilter();
-    bool affectsTransparentBlack() const override;
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkRectShaderImageFilter)

src/core/SkImageFilter.cpp

@@ -284,23 +284,6 @@ void SkImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
     }
 }
 
-bool SkImageFilter::canComputeFastBounds() const {
-    if (this->affectsTransparentBlack()) {
-        return false;
-    }
-    for (int i = 0; i < fInputCount; i++) {
-        SkImageFilter* input = this->getInput(i);
-        if (input && !input->canComputeFastBounds()) {
-            return false;
-        }
-    }
-    return true;
-}
-
-bool SkImageFilter::affectsTransparentBlack() const {
-    return false;
-}
-
 bool SkImageFilter::onFilterImage(Proxy*, const SkBitmap&, const Context&,
                                   SkBitmap*, SkIPoint*) const {
     return false;

src/core/SkPaint.cpp

@@ -2063,16 +2063,6 @@ bool SkPaint::getFillPath(const SkPath& src, SkPath* dst, const SkRect* cullRect
     return !rec.isHairlineStyle();
 }
 
-bool SkPaint::canComputeFastBounds() const {
-    if (this->getLooper()) {
-        return this->getLooper()->canComputeFastBounds(*this);
-    }
-    if (this->getImageFilter() && !this->getImageFilter()->canComputeFastBounds()) {
-        return false;
-    }
-    return !this->getRasterizer();
-}
-
 const SkRect& SkPaint::doComputeFastBounds(const SkRect& origSrc,
                                            SkRect* storage,
                                            Style style) const {

src/effects/SkColorFilterImageFilter.cpp

@@ -98,10 +98,6 @@ bool SkColorFilterImageFilter::onIsColorFilterNode(SkColorFilter** filter) const
     return false;
 }
 
-bool SkColorFilterImageFilter::affectsTransparentBlack() const {
-    return fColorFilter->affectsTransparentBlack();
-}
-
 #ifndef SK_IGNORE_TO_STRING
 void SkColorFilterImageFilter::toString(SkString* str) const {
     str->appendf("SkColorFilterImageFilter: (");

src/effects/SkRectShaderImageFilter.cpp

@@ -79,10 +79,6 @@ bool SkRectShaderImageFilter::onFilterImage(Proxy* proxy,
     return true;
 }
 
-bool SkRectShaderImageFilter::affectsTransparentBlack() const {
-    return true;
-}
-
 #ifndef SK_IGNORE_TO_STRING
 void SkRectShaderImageFilter::toString(SkString* str) const {
     str->appendf("SkRectShaderImageFilter: (");

tests/ImageFilterTest.cpp

@@ -30,7 +30,6 @@
 #include "SkReadBuffer.h"
 #include "SkRect.h"
 #include "SkRectShaderImageFilter.h"
-#include "SkTableColorFilter.h"
 #include "SkTileImageFilter.h"
 #include "SkXfermodeImageFilter.h"
 #include "Test.h"
@@ -1160,58 +1159,6 @@ DEF_TEST(PartialCropRect, reporter) {
     REPORTER_ASSERT(reporter, result.height() == 30);
 }
 
-DEF_TEST(ImageFilterCanComputeFastBounds, reporter) {
-
-    SkPoint3 location = SkPoint3::Make(0, 0, SK_Scalar1);
-    SkAutoTUnref<SkImageFilter> lighting(SkLightingImageFilter::CreatePointLitDiffuse(
-          location, SK_ColorGREEN, 0, 0));
-    REPORTER_ASSERT(reporter, !lighting->canComputeFastBounds());
-
-    SkAutoTUnref<SkImageFilter> gray(make_grayscale(nullptr, nullptr));
-    REPORTER_ASSERT(reporter, gray->canComputeFastBounds());
-    {
-        SkColorFilter* grayCF;
-        REPORTER_ASSERT(reporter, gray->asAColorFilter(&grayCF));
-        REPORTER_ASSERT(reporter, !grayCF->affectsTransparentBlack());
-        grayCF->unref();
-    }
-    REPORTER_ASSERT(reporter, gray->canComputeFastBounds());
-
-    SkAutoTUnref<SkImageFilter> grayBlur(SkBlurImageFilter::Create(SK_Scalar1, SK_Scalar1, gray.get()));
-    REPORTER_ASSERT(reporter, grayBlur->canComputeFastBounds());
-
-    SkScalar greenMatrix[20] = { 0, 0, 0, 0, 0,
-                                 0, 0, 0, 0, 1,
-                                 0, 0, 0, 0, 0,
-                                 0, 0, 0, 0, 1 };
-    SkAutoTUnref<SkColorFilter> greenCF(SkColorMatrixFilter::Create(greenMatrix));
-    SkAutoTUnref<SkImageFilter> green(SkColorFilterImageFilter::Create(greenCF));
-
-    REPORTER_ASSERT(reporter, greenCF->affectsTransparentBlack());
-    REPORTER_ASSERT(reporter, !green->canComputeFastBounds());
-
-    SkAutoTUnref<SkImageFilter> greenBlur(SkBlurImageFilter::Create(SK_Scalar1, SK_Scalar1, green.get()));
-    REPORTER_ASSERT(reporter, !greenBlur->canComputeFastBounds());
-
-    uint8_t allOne[256], identity[256];
-    for (int i = 0; i < 256; ++i) {
-        identity[i] = i;
-        allOne[i] = 255;
-    }
-
-    SkAutoTUnref<SkColorFilter> identityCF(
-        SkTableColorFilter::CreateARGB(identity, identity, identity, allOne));
-    SkAutoTUnref<SkImageFilter> identityFilter(SkColorFilterImageFilter::Create(identityCF.get()));
-    REPORTER_ASSERT(reporter, !identityCF->affectsTransparentBlack());
-    REPORTER_ASSERT(reporter, identityFilter->canComputeFastBounds());
-
-    SkAutoTUnref<SkColorFilter> forceOpaqueCF(
-        SkTableColorFilter::CreateARGB(allOne, identity, identity, identity));
-    SkAutoTUnref<SkImageFilter> forceOpaque(SkColorFilterImageFilter::Create(forceOpaqueCF.get()));
-    REPORTER_ASSERT(reporter, forceOpaqueCF->affectsTransparentBlack());
-    REPORTER_ASSERT(reporter, !forceOpaque->canComputeFastBounds());
-}
-
 #if SK_SUPPORT_GPU
 
 DEF_GPUTEST(ImageFilterCropRectGPU, reporter, factory) {