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_);

[enne (OOO), 2015/11/18 21:31:58]

I get that you're trying to check that you covered everything.  But, not all of
these tests actually paint anything.

What do you think about just setting this to a default value of an empty rect so
that every test that uses a FakeContentLayerClient doesn't have to update this
value?

[chrishtr, 2015/11/18 22:33:11]

Per offline conversation, there were actually a whole bunch of tests that failed
that tried to draw tiles. I don't know the exact percentage, but I think it was
enough to make it reasonable to just leave it.

+  return gfx::Rect(bounds_);
+}
+
 scoped_refptr<DisplayItemList>
 FakeContentLayerClient::PaintContentsToDisplayList(
     const gfx::Rect& clip,