Fix for 424682: Draw correct repaint regions instead of a conservative bounding box

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index e819afd860d412784301915fe1fcbd7ac857aa67..b5bd9a0ef04e8cbc52d0708794f6594ca0f34ec3 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -605,6 +605,10 @@ skia::RefPtr<SkPicture> PictureLayerImpl::GetPicture() {
   return raster_source_->GetFlattenedPicture();
 }
 
+Region PictureLayerImpl::GetInvalidationRegion() {
+  return invalidation_;

[danakj, 2015/02/27 21:10:48]

you can intersect it here

[danakj, 2015/02/27 21:25:35]

With a comment explaining why you're doing so based on what we've learnt in this
CL :)

+}
+
 scoped_refptr<Tile> PictureLayerImpl::CreateTile(
     float contents_scale,
     const gfx::Rect& content_rect) {