cc: don't add low-res tiling to GPU rasterized layers.

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 1412 matching lines @@
   Tile* tile = pending_layer_->tilings()->tiling_at(0)->AllTilesForTesting()[0];
   EXPECT_EQ(host_impl_.settings().default_tile_size.ToString(),
             tile->content_rect().size().ToString());
 
   // Tell the layer to use GPU rasterization.
   pending_layer_->SetShouldUseGpuRasterization(true);
   EXPECT_EQ(0u, pending_layer_->tilings()->num_tilings());
 
   pending_layer_->CalculateContentsScale(
       1.f, 1.f, 1.f, false, &result_scale_x, &result_scale_y, &result_bounds);
-  ASSERT_EQ(2u, pending_layer_->tilings()->num_tilings());
+  ASSERT_EQ(1u, pending_layer_->tilings()->num_tilings());
 
   pending_layer_->tilings()->tiling_at(0)->CreateAllTilesForTesting();
 
   // Tile size should now equal default_tile_size_gpu.
   Tile* tile_gpu =
       pending_layer_->tilings()->tiling_at(0)->AllTilesForTesting()[0];
   EXPECT_EQ(default_tile_size_gpu.ToString(),
             tile_gpu->content_rect().size().ToString());
 }
 
@@ skipping 108 matching lines @@
       TestContextProvider::Create(), NULL));
 
   // These will crash PictureLayerImpl if this is not true.
   ASSERT_TRUE(host_impl_.pending_tree()->needs_update_draw_properties());
   ASSERT_TRUE(host_impl_.active_tree()->needs_update_draw_properties());
   host_impl_.active_tree()->UpdateDrawProperties();
 }
 
 }  // namespace
 }  // namespace cc