Force use of and cache render surface.

cc/trees/damage_tracker.h

Index: cc/trees/damage_tracker.h
diff --git a/cc/trees/damage_tracker.h b/cc/trees/damage_tracker.h
index 751eeb977e5b749503ec8c83fb9224cdb2aed576..e595a93373df86032c9374c5ba0fc7c2d7af8e97 100644
--- a/cc/trees/damage_tracker.h
+++ b/cc/trees/damage_tracker.h
@@ -41,6 +41,10 @@ class CC_EXPORT DamageTracker {
 
   bool GetDamageRectIfValid(gfx::Rect* rect);
 
+  bool has_property_change_on_contributing_render_surface() const {
+    return has_property_change_on_contributing_render_surface_;
+  }
+
  private:
   DamageTracker();
 
@@ -144,6 +148,10 @@ class CC_EXPORT DamageTracker {
   // Damage accumulated since the last call to PrepareForUpdate().
   DamageAccumulator damage_for_this_update_;
 
+  // Property changes from contributing render surface accumulated since the
+  // last call to PrepareForUpdate().
+  bool has_property_change_on_contributing_render_surface_;
+
   DISALLOW_COPY_AND_ASSIGN(DamageTracker);
 };