SkRectShaderImageFilter: add a workaround for the zero-sized rects currently passed by Blink. Add …

src/effects/SkRectShaderImageFilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRectShaderImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkFlattenableBuffers.h"
 #include "SkShader.h"
 
 SkRectShaderImageFilter* SkRectShaderImageFilter::Create(SkShader* s, const SkRect& rect) {
     SkASSERT(s);
 #ifdef SK_CROP_RECT_IS_INT
     SkIRect cropRect;
-    rect.roundOut(&cropRect);
+    if (rect.width() == 0 || rect.height() == 0) {
+        cropRect = SkIRect::MakeLargest();
+    } else {
+        rect.roundOut(&cropRect);
+    }
 #else
-    CropRect cropRect(rect);
+    uint32_t flags = CropRect::kHasAll_CropEdge;
+    if (rect.width() == 0 || rect.height() == 0) {
+        flags = 0x0;
+    }
+    CropRect cropRect(rect, flags);
 #endif
     return SkNEW_ARGS(SkRectShaderImageFilter, (s, &cropRect));
 }
 
 SkRectShaderImageFilter::SkRectShaderImageFilter(SkShader* s, const CropRect* cropRect)
   : INHERITED(NULL, cropRect)
   , fShader(s) {
     SkASSERT(s);
     s->ref();
 }
@@ skipping 32 matching lines @@
     SkMatrix matrix;
     matrix.setTranslate(-SkIntToScalar(bounds.fLeft), -SkIntToScalar(bounds.fTop));
     fShader->setLocalMatrix(matrix);
     SkRect rect = SkRect::MakeWH(SkIntToScalar(bounds.width()), SkIntToScalar(bounds.height()));
     canvas.drawRect(rect, paint);
     *result = device.get()->accessBitmap(false);
     offset->fX += bounds.fLeft;
     offset->fY += bounds.fTop;
     return true;
 }