cc: Move gpu rasterization flag from tree-impl to tree-host-impl.

cc/layers/picture_layer_impl.h

Index: cc/layers/picture_layer_impl.h
diff --git a/cc/layers/picture_layer_impl.h b/cc/layers/picture_layer_impl.h
index 80d09dde721ad2e533c11d819f4241e986c6327c..bbf5030ba2a0b7ce4d6ee6f8f7a5e37600f91bac 100644
--- a/cc/layers/picture_layer_impl.h
+++ b/cc/layers/picture_layer_impl.h
@@ -132,10 +132,6 @@ class CC_EXPORT PictureLayerImpl
 
   virtual void RunMicroBenchmark(MicroBenchmarkImpl* benchmark) OVERRIDE;
 
-  bool use_gpu_rasterization() const {
-    return layer_tree_impl()->use_gpu_rasterization();
-  }
-
   // Functions used by tile manager.
   void DidUnregisterLayer();
   PictureLayerImpl* GetTwinLayer() { return twin_layer_; }
@@ -153,7 +149,8 @@ class CC_EXPORT PictureLayerImpl
   void ManageTilings(bool animating_transform_to_screen,
                      float maximum_animation_contents_scale);
   bool ShouldHaveLowResTiling() const {
-    return should_use_low_res_tiling_ && !use_gpu_rasterization();
+    return should_use_low_res_tiling_ &&
+           !layer_tree_impl()->use_gpu_rasterization();
   }
   virtual bool ShouldAdjustRasterScale(
       bool animating_transform_to_screen) const;