Add flag for drawing layers to screen with Ganesh

cc/resources/picture_pile_impl.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_RESOURCES_PICTURE_PILE_IMPL_H_
 #define CC_RESOURCES_PICTURE_PILE_IMPL_H_
 
 #include <list>
 #include <map>
 #include <vector>
@@ skipping 29 matching lines @@
   };
 
   // Raster a subrect of this PicturePileImpl into the given canvas.
   // It's only safe to call paint on a cloned version.  It is assumed
   // that contents_scale has already been applied to this canvas.
   // Writes the total number of pixels rasterized and the time spent
   // rasterizing to the stats if the respective pointer is not
   // NULL. When slow-down-raster-scale-factor is set to a value
   // greater than 1, the reported rasterize time is the minimum
   // measured value over all runs.
-  void Raster(
+  void RasterDirect(
       SkCanvas* canvas,
       gfx::Rect canvas_rect,
       float contents_scale,
+      RasterStats* raster_stats);
+
+  // Similar to the above RasterDirect method, but this is a convenience method
+  // for when it is known that the raster is going to an intermediate bitmap
+  // that itself will then be blended and thus that a canvas clear is required.
+  void RasterToBitmap(
+      SkCanvas* canvas,
+      gfx::Rect canvas_rect,
+      float contents_scale,
       RasterStats* raster_stats);
 
   skia::RefPtr<SkPicture> GetFlattenedPicture();
 
   struct CC_EXPORT Analysis {
     Analysis();
     ~Analysis();
 
     bool is_solid_color;
     bool has_text;
@@ skipping 58 matching lines @@
   // instance.  This member variable must be last so that other member
   // variables have already been initialized and can be clonable.
   const ClonesForDrawing clones_for_drawing_;
 
   DISALLOW_COPY_AND_ASSIGN(PicturePileImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_PILE_IMPL_H_