cc: Move gpu rasterization flag from LayerImpl to LayerTreeImpl.

cc/layers/picture_layer_impl_unittest.cc

Index: cc/layers/picture_layer_impl_unittest.cc
diff --git a/cc/layers/picture_layer_impl_unittest.cc b/cc/layers/picture_layer_impl_unittest.cc
index 114c8a9bae3355a225ded8f2b318cbc603033559..7ba85a653c14903ec0d8f6d18b3c3eb169db2295 100644
--- a/cc/layers/picture_layer_impl_unittest.cc
+++ b/cc/layers/picture_layer_impl_unittest.cc
@@ -1672,7 +1672,7 @@ TEST_F(PictureLayerImplTest, NoLowResTilingWithGpuRasterization) {
   gfx::Size result_bounds;
 
   SetupDefaultTrees(layer_bounds);
-  EXPECT_FALSE(pending_layer_->ShouldUseGpuRasterization());
+  EXPECT_FALSE(pending_layer_->use_gpu_rasterization());
   EXPECT_EQ(0u, pending_layer_->tilings()->num_tilings());
   pending_layer_->CalculateContentsScale(1.f,
                                          1.f,
@@ -1685,9 +1685,10 @@ TEST_F(PictureLayerImplTest, NoLowResTilingWithGpuRasterization) {
   // Should have a low-res and a high-res tiling.
   ASSERT_EQ(2u, pending_layer_->tilings()->num_tilings());
 
-  pending_layer_->SetUseGpuRasterization(true);
-  EXPECT_TRUE(pending_layer_->ShouldUseGpuRasterization());
-  EXPECT_EQ(0u, pending_layer_->tilings()->num_tilings());
+  ResetTilingsAndRasterScales();
+
+  host_impl_.pending_tree()->set_use_gpu_rasterization(true);
+  EXPECT_TRUE(pending_layer_->use_gpu_rasterization());
   pending_layer_->CalculateContentsScale(1.f,
                                          1.f,
                                          1.f,
@@ -1903,8 +1904,10 @@ TEST_F(PictureLayerImplTest, HighResTilingDuringAnimationForCpuRasterization) {
 TEST_F(PictureLayerImplTest, HighResTilingDuringAnimationForGpuRasterization) {
   gfx::Size tile_size(host_impl_.settings().default_tile_size);
   SetupDefaultTrees(tile_size);
-  pending_layer_->SetUseGpuRasterization(true);
-  active_layer_->SetUseGpuRasterization(true);
+  host_impl_.pending_tree()->set_use_gpu_rasterization(true);
+  host_impl_.active_tree()->set_use_gpu_rasterization(true);
+  EXPECT_TRUE(pending_layer_->use_gpu_rasterization());
+  EXPECT_TRUE(active_layer_->use_gpu_rasterization());
 
   float contents_scale = 1.f;
   float device_scale = 1.f;