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

cc/test/fake_content_layer_client.cc

Index: cc/test/fake_content_layer_client.cc
diff --git a/cc/test/fake_content_layer_client.cc b/cc/test/fake_content_layer_client.cc
index bfa7c19b36ab6ff22683d1ef01a30aa21400a326..a328c3371b5c4e836b84d200b9124dbed5309d9b 100644
--- a/cc/test/fake_content_layer_client.cc
+++ b/cc/test/fake_content_layer_client.cc
@@ -35,6 +35,11 @@ FakeContentLayerClient::FakeContentLayerClient()
 FakeContentLayerClient::~FakeContentLayerClient() {
 }
 
+gfx::Rect FakeContentLayerClient::PaintableRegion() {
+  CHECK(bounds_set_);
+  return gfx::Rect(bounds_);
+}
+
 scoped_refptr<DisplayItemList>
 FakeContentLayerClient::PaintContentsToDisplayList(
     const gfx::Rect& clip,