cc: Make PaintCanvas abstract

third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1204 matching lines @@
     return;
 
   IntRect rect = intersection(tracking->lastInterestRect, interestRect());
   if (rect.isEmpty())
     return;
 
   SkBitmap oldBitmap;
   oldBitmap.allocPixels(
       SkImageInfo::MakeN32Premul(rect.width(), rect.height()));
   {
-    PaintCanvas canvas(oldBitmap);
+    SkiaPaintCanvas canvas(oldBitmap);
     canvas.clear(SK_ColorTRANSPARENT);
     canvas.translate(-rect.x(), -rect.y());
     canvas.drawPicture(tracking->lastPaintedRecord.get());
   }
 
   SkBitmap newBitmap;
   newBitmap.allocPixels(
       SkImageInfo::MakeN32Premul(rect.width(), rect.height()));
   {
-    PaintCanvas canvas(newBitmap);
+    SkiaPaintCanvas canvas(newBitmap);
     canvas.clear(SK_ColorTRANSPARENT);
     canvas.translate(-rect.x(), -rect.y());
     canvas.drawPicture(&newRecord);
   }
 
   oldBitmap.lockPixels();
   newBitmap.lockPixels();
   int mismatchingPixels = 0;
   static const int maxMismatchesToReport = 50;
   for (int bitmapY = 0; bitmapY < rect.height(); ++bitmapY) {
@@ skipping 44 matching lines @@
 void showGraphicsLayerTree(const blink::GraphicsLayer* layer) {
   if (!layer) {
     LOG(INFO) << "Cannot showGraphicsLayerTree for (nil).";
     return;
   }
 
   String output = layer->layerTreeAsText(blink::LayerTreeIncludesDebugInfo);
   LOG(INFO) << output.utf8().data();
 }
 #endif