Turn off computation of the interest rect in cc in synchronized paint mode.

cc/layers/picture_image_layer.cc

Index: cc/layers/picture_image_layer.cc
diff --git a/cc/layers/picture_image_layer.cc b/cc/layers/picture_image_layer.cc
index f2caeaf199d58086eb5756533efefaadaad13566..d8ddd69c70c0778ad6fc7c4e0e31b71343a93d24 100644
--- a/cc/layers/picture_image_layer.cc
+++ b/cc/layers/picture_image_layer.cc
@@ -49,6 +49,10 @@ void PictureImageLayer::SetImage(skia::RefPtr<const SkImage> image) {
   SetNeedsDisplay();
 }
 
+gfx::Rect PictureImageLayer::PaintableRegion() {
+  return gfx::Rect(0, 0, bounds().width(), bounds().height());
+}
+
 scoped_refptr<DisplayItemList> PictureImageLayer::PaintContentsToDisplayList(
     const gfx::Rect& clip,
     ContentLayerClient::PaintingControlSetting painting_control) {