diff --git a/gm/matrixconvolution.cpp b/gm/matrixconvolution.cpp
index 6d16f8dfa7..3b159f455b 100644
--- a/gm/matrixconvolution.cpp
+++ b/gm/matrixconvolution.cpp
@@ -86,21 +86,22 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         canvas->clear(SK_ColorBLACK);
         SkIPoint kernelOffset = SkIPoint::Make(1, 0);
+        SkImageFilter::CropRect rect(SkRect::Make(fBitmap.bounds()));
         for (int x = 10; x < 310; x += 100) {
-            this->draw(canvas, x, 10, kernelOffset, MCIF::kClamp_TileMode, true);
-            this->draw(canvas, x, 110, kernelOffset, MCIF::kClampToBlack_TileMode, true);
-            this->draw(canvas, x, 210, kernelOffset, MCIF::kRepeat_TileMode, true);
+            this->draw(canvas, x, 10, kernelOffset, MCIF::kClamp_TileMode, true, &rect);
+            this->draw(canvas, x, 110, kernelOffset, MCIF::kClampToBlack_TileMode, true, &rect);
+            this->draw(canvas, x, 210, kernelOffset, MCIF::kRepeat_TileMode, true, &rect);
             kernelOffset.fY++;
         }
         kernelOffset.fY = 1;
-        SkImageFilter::CropRect rect(SkRect::MakeXYWH(10, 5, 60, 60));
-        this->draw(canvas, 310, 10, kernelOffset, MCIF::kClamp_TileMode, true, &rect);
-        this->draw(canvas, 310, 110, kernelOffset, MCIF::kClampToBlack_TileMode, true, &rect);
-        this->draw(canvas, 310, 210, kernelOffset, MCIF::kRepeat_TileMode, true, &rect);
+        SkImageFilter::CropRect smallRect(SkRect::MakeXYWH(10, 5, 60, 60));
+        this->draw(canvas, 310, 10, kernelOffset, MCIF::kClamp_TileMode, true, &smallRect);
+        this->draw(canvas, 310, 110, kernelOffset, MCIF::kClampToBlack_TileMode, true, &smallRect);
+        this->draw(canvas, 310, 210, kernelOffset, MCIF::kRepeat_TileMode, true, &smallRect);
 
-        this->draw(canvas, 410, 10, kernelOffset, MCIF::kClamp_TileMode, false);
-        this->draw(canvas, 410, 110, kernelOffset, MCIF::kClampToBlack_TileMode, false);
-        this->draw(canvas, 410, 210, kernelOffset, MCIF::kRepeat_TileMode, false);
+        this->draw(canvas, 410, 10, kernelOffset, MCIF::kClamp_TileMode, false, &rect);
+        this->draw(canvas, 410, 110, kernelOffset, MCIF::kClampToBlack_TileMode, false, &rect);
+        this->draw(canvas, 410, 210, kernelOffset, MCIF::kRepeat_TileMode, false, &rect);
     }
 
 private:
diff --git a/include/core/SkImageFilter.h b/include/core/SkImageFilter.h
index d90df29c8b..909a2f8284 100644
--- a/include/core/SkImageFilter.h
+++ b/include/core/SkImageFilter.h
@@ -199,12 +199,7 @@ public:
      *  replaced by the returned colorfilter. i.e. the two effects will affect drawing in the
      *  same way.
      */
-    bool asAColorFilter(SkColorFilter** filterPtr) const {
-        return this->countInputs() > 0 &&
-               NULL == this->getInput(0) &&
-               !this->affectsTransparentBlack() &&
-               this->isColorFilterNode(filterPtr);
-    }
+    bool asAColorFilter(SkColorFilter** filterPtr) const;
 
     /**
      *  Returns the number of inputs this filter will accept (some inputs can
@@ -240,7 +235,7 @@ public:
     virtual void computeFastBounds(const SkRect&, SkRect*) const;
 
     // Can this filter DAG compute the resulting bounds of an object-space rectangle?
-    bool canComputeFastBounds() const;
+    virtual bool canComputeFastBounds() const;
 
     /**
      *  If this filter can be represented by another filter + a localMatrix, return that filter,
@@ -410,14 +405,6 @@ protected:
     virtual bool asFragmentProcessor(GrFragmentProcessor**, 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();
diff --git a/include/effects/SkColorFilterImageFilter.h b/include/effects/SkColorFilterImageFilter.h
index 200ec86500..db5d842c2f 100644
--- a/include/effects/SkColorFilterImageFilter.h
+++ b/include/effects/SkColorFilterImageFilter.h
@@ -25,7 +25,7 @@ protected:
     bool onFilterImage(Proxy*, const SkBitmap& src, const Context&, SkBitmap* result,
                        SkIPoint* loc) const override;
     bool onIsColorFilterNode(SkColorFilter**) const override;
-    bool affectsTransparentBlack() const override;
+    bool canComputeFastBounds() const override;
 
 private:
     SkColorFilterImageFilter(SkColorFilter* cf,
diff --git a/include/effects/SkLightingImageFilter.h b/include/effects/SkLightingImageFilter.h
index fb356c52e4..33cfceccb2 100644
--- a/include/effects/SkLightingImageFilter.h
+++ b/include/effects/SkLightingImageFilter.h
@@ -49,7 +49,7 @@ protected:
     void flatten(SkWriteBuffer&) const override;
     const SkImageFilterLight* light() const { return fLight.get(); }
     SkScalar surfaceScale() const { return fSurfaceScale; }
-    bool affectsTransparentBlack() const override { return true; }
+    bool canComputeFastBounds() const override { return false; }
 
 private:
     typedef SkImageFilter INHERITED;
diff --git a/include/effects/SkMatrixConvolutionImageFilter.h b/include/effects/SkMatrixConvolutionImageFilter.h
index 76349f430c..ef5ff72494 100644
--- a/include/effects/SkMatrixConvolutionImageFilter.h
+++ b/include/effects/SkMatrixConvolutionImageFilter.h
@@ -80,7 +80,7 @@ protected:
     bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
                        SkBitmap* result, SkIPoint* loc) const override;
     bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*) const override;
-
+    bool canComputeFastBounds() const override;
 
 #if SK_SUPPORT_GPU
     bool asFragmentProcessor(GrFragmentProcessor**, GrTexture*, const SkMatrix&,
diff --git a/include/effects/SkRectShaderImageFilter.h b/include/effects/SkRectShaderImageFilter.h
index 9798af2d64..9ac116ae5f 100644
--- a/include/effects/SkRectShaderImageFilter.h
+++ b/include/effects/SkRectShaderImageFilter.h
@@ -29,7 +29,7 @@ public:
     static SkImageFilter* Create(SkShader* s, const SkRect& rect);
     static SkImageFilter* Create(SkShader* s, const CropRect* rect = NULL);
 
-    bool affectsTransparentBlack() const override;
+    bool canComputeFastBounds() const override;
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkRectShaderImageFilter)
diff --git a/src/core/SkImageFilter.cpp b/src/core/SkImageFilter.cpp
index 6a3286ed67..3b2b27710d 100644
--- a/src/core/SkImageFilter.cpp
+++ b/src/core/SkImageFilter.cpp
@@ -309,9 +309,6 @@ 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()) {
@@ -321,10 +318,6 @@ bool SkImageFilter::canComputeFastBounds() const {
     return true;
 }
 
-bool SkImageFilter::affectsTransparentBlack() const {
-    return false;
-}
-
 bool SkImageFilter::onFilterImage(Proxy*, const SkBitmap&, const Context&,
                                   SkBitmap*, SkIPoint*) const {
     return false;
@@ -391,6 +384,18 @@ bool SkImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, const Cont
     return false;
 }
 
+bool SkImageFilter::asAColorFilter(SkColorFilter** filterPtr) const {
+    SkASSERT(nullptr != filterPtr);
+    if (!this->isColorFilterNode(filterPtr)) {
+        return false;
+    }
+    if (nullptr != this->getInput(0) || (*filterPtr)->affectsTransparentBlack()) {
+        (*filterPtr)->unref();
+        return false;
+    }
+    return true;
+}
+
 bool SkImageFilter::applyCropRect(const Context& ctx, const SkBitmap& src,
                                   const SkIPoint& srcOffset, SkIRect* dstBounds,
                                   SkIRect* srcBounds) const {
diff --git a/src/effects/SkColorFilterImageFilter.cpp b/src/effects/SkColorFilterImageFilter.cpp
index 8d394aa17b..b0e47505a7 100644
--- a/src/effects/SkColorFilterImageFilter.cpp
+++ b/src/effects/SkColorFilterImageFilter.cpp
@@ -99,8 +99,11 @@ bool SkColorFilterImageFilter::onIsColorFilterNode(SkColorFilter** filter) const
     return false;
 }
 
-bool SkColorFilterImageFilter::affectsTransparentBlack() const {
-    return fColorFilter->affectsTransparentBlack();
+bool SkColorFilterImageFilter::canComputeFastBounds() const {
+    if (fColorFilter->affectsTransparentBlack()) {
+        return false;
+    }
+    return INHERITED::canComputeFastBounds();
 }
 
 #ifndef SK_IGNORE_TO_STRING
diff --git a/src/effects/SkMatrixConvolutionImageFilter.cpp b/src/effects/SkMatrixConvolutionImageFilter.cpp
index e58eec10f4..7c5dd8368f 100644
--- a/src/effects/SkMatrixConvolutionImageFilter.cpp
+++ b/src/effects/SkMatrixConvolutionImageFilter.cpp
@@ -335,6 +335,12 @@ bool SkMatrixConvolutionImageFilter::onFilterBounds(const SkIRect& src, const Sk
     return true;
 }
 
+bool SkMatrixConvolutionImageFilter::canComputeFastBounds() const {
+    // Because the kernel is applied in device-space, we have no idea what
+    // pixels it will affect in object-space.
+    return false;
+}
+
 #if SK_SUPPORT_GPU
 
 static GrTextureDomain::Mode convert_tilemodes(
diff --git a/src/effects/SkRectShaderImageFilter.cpp b/src/effects/SkRectShaderImageFilter.cpp
index 14837d02b1..00964b5ffb 100644
--- a/src/effects/SkRectShaderImageFilter.cpp
+++ b/src/effects/SkRectShaderImageFilter.cpp
@@ -79,8 +79,11 @@ bool SkRectShaderImageFilter::onFilterImage(Proxy* proxy,
     return true;
 }
 
-bool SkRectShaderImageFilter::affectsTransparentBlack() const {
-    return true;
+bool SkRectShaderImageFilter::canComputeFastBounds() const {
+    // http:skbug.com/4627: "make computeFastBounds and onFilterBounds() CropRect-aware"
+    // computeFastBounds() doesn't currently take the crop rect into account,
+    // so we can't compute it. If a full crop rect is set, we should return true here.
+    return false;
 }
 
 #ifndef SK_IGNORE_TO_STRING