cc: Move gpu rasterization flag from LayerImpl to LayerTreeImpl.

cc/trees/layer_tree_impl.h

Index: cc/trees/layer_tree_impl.h
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index bc488db3c54c7bf96bc4edf7b8e479841695be49..56f4ea2e89fc83f82ab288d2807ea5b688d17ddb 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -163,6 +163,11 @@ class CC_EXPORT LayerTreeImpl {
   }
   float sent_page_scale_delta() const { return sent_page_scale_delta_; }
 
+  void set_use_gpu_rasterization(bool use_gpu) {
+    use_gpu_rasterization_ = use_gpu;
+  }
+  bool use_gpu_rasterization() const { return use_gpu_rasterization_; }
+
   // Updates draw properties and render surface layer list, as well as tile
   // priorities.
   void UpdateDrawProperties();
@@ -282,6 +287,7 @@ class CC_EXPORT LayerTreeImpl {
   // frame. Used for rendering and input event hit testing.
   LayerImplList render_surface_layer_list_;
 
+  bool use_gpu_rasterization_;
   bool contents_textures_purged_;
   bool requires_high_res_to_draw_;
   bool viewport_size_invalid_;