Reland of Implement canComputeFastBounds() for image filters.

src/core/SkPaint.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPaint.h"
 #include "SkAnnotation.h"
 #include "SkAutoKern.h"
@@ skipping 2045 matching lines @@
             // since we know we're just going to delete tmpPath when we return,
             // so the swap saves that copy.
             dst->swap(tmpPath);
         } else {
             *dst = *srcPtr;
         }
     }
     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 {
     SkASSERT(storage);
 
     const SkRect* src = &origSrc;
 
     if (this->getLooper()) {
         SkASSERT(this->getLooper()->canComputeFastBounds(*this));
         this->getLooper()->computeFastBounds(*this, *src, storage);
@@ skipping 341 matching lines @@
 }
 
 uint32_t SkPaint::getHash() const {
     // We're going to hash 10 pointers and 7 32-bit values, finishing up with fBitfields,
     // so fBitfields should be 10 pointers and 6 32-bit values from the start.
     SK_COMPILE_ASSERT(offsetof(SkPaint, fBitfields) == 10 * sizeof(void*) + 6 * sizeof(uint32_t),
                       SkPaint_notPackedTightly);
     return SkChecksum::Murmur3(reinterpret_cast<const uint32_t*>(this),
                                offsetof(SkPaint, fBitfields) + sizeof(fBitfields));
 }