Fork: Clip a layer when its render target's render surface is clipped.

Cherry pick from Chromium:
https://codereview.chromium.org/751453005/
Only the fix part from the original CL is cherry picked. 
The other changes in the original CL are all tests.

Original description:
An empty clip rect of a render surface does not necessarily mean
the surface is unclippped.

BUG=435797

BUG: 18343246
Change-Id: I56b8f2d557b21aa75619157e611ab4da9bd4688c
1 file changed