Add flag for drawing layers to screen with Ganesh

cc/layers/picture_layer_impl_unittest.cc

 // Copyright 2013 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.
 
 #include "cc/layers/picture_layer_impl.h"
 
 #include <utility>
 
 #include "cc/layers/append_quads_data.h"
 #include "cc/layers/picture_layer.h"
@@ skipping 206 matching lines @@
       MockCanvas mock_canvas(&device);
       active_pile->Raster(&mock_canvas,
                           (*tile_iter)->content_rect(),
                           1.0f,
                           NULL);
 
       // This test verifies that when drawing the contents of a specific tile
       // at content scale 1.0, the playback canvas never receives content from
       // neighboring tiles which indicates that the tile grid embedded in
       // SkPicture is perfectly aligned with the compositor's tiles.
-      // Note: There are two rects: the initial clear and the explicitly
-      // recorded rect. We only care about the second one.
-      EXPECT_EQ(2u, mock_canvas.rects_.size());
-      EXPECT_RECT_EQ(*rect_iter, mock_canvas.rects_[1]);
+      EXPECT_EQ(1u, mock_canvas.rects_.size());

[enne (OOO), 2013/05/13 19:33:10]

This change is because the clear moved to RasterToBitmap and not Raster. 
Testing just Raster seemed cleaner.

+      EXPECT_RECT_EQ(*rect_iter, mock_canvas.rects_[0]);
       rect_iter++;
     }
   }
 
   FakeImplProxy proxy_;
   FakeLayerTreeHostImpl host_impl_;
   int id_;
   TestablePictureLayerImpl* pending_layer_;
   TestablePictureLayerImpl* active_layer_;
 
@@ skipping 611 matching lines @@
   AppendQuadsData data;
   data.allow_tile_draw_quads = false;
   active_layer_->AppendQuads(&quad_culler, &data);
 
   ASSERT_EQ(1U, quad_culler.quad_list().size());
   EXPECT_EQ(DrawQuad::PICTURE_CONTENT, quad_culler.quad_list()[0]->material);
 }
 
 }  // namespace
 }  // namespace cc