cc : Stop calculating visible rects on main thread

cc/trees/property_tree_builder.h

Index: cc/trees/property_tree_builder.h
diff --git a/cc/trees/property_tree_builder.h b/cc/trees/property_tree_builder.h
index 23d7e1c10db3bad9e3dd1145d0c63bfe97befbdc..49a91751234bb5d655403b1b8fa79bc536339847 100644
--- a/cc/trees/property_tree_builder.h
+++ b/cc/trees/property_tree_builder.h
@@ -16,17 +16,18 @@ class LayerTreeHost;
 
 class PropertyTreeBuilder {
  public:
-  static void BuildPropertyTrees(Layer* root_layer,
-                                 const Layer* page_scale_layer,
-                                 const Layer* inner_viewport_scroll_layer,
-                                 const Layer* outer_viewport_scroll_layer,
-                                 const Layer* overscroll_elasticity_layer,
-                                 const gfx::Vector2dF& elastic_overscroll,
-                                 float page_scale_factor,
-                                 float device_scale_factor,
-                                 const gfx::Rect& viewport,
-                                 const gfx::Transform& device_transform,
-                                 PropertyTrees* property_trees);
+  static void CC_EXPORT
+  BuildPropertyTrees(Layer* root_layer,
+                     const Layer* page_scale_layer,
+                     const Layer* inner_viewport_scroll_layer,
+                     const Layer* outer_viewport_scroll_layer,
+                     const Layer* overscroll_elasticity_layer,
+                     const gfx::Vector2dF& elastic_overscroll,
+                     float page_scale_factor,
+                     float device_scale_factor,
+                     const gfx::Rect& viewport,
+                     const gfx::Transform& device_transform,
+                     PropertyTrees* property_trees);
   static void BuildPropertyTrees(LayerImpl* root_layer,
                                  const LayerImpl* page_scale_layer,
                                  const LayerImpl* inner_viewport_scroll_layer,