Overlays: Remove special casing of primary overlay plane

cc/test/fake_output_surface.cc

Index: cc/test/fake_output_surface.cc
diff --git a/cc/test/fake_output_surface.cc b/cc/test/fake_output_surface.cc
index 4ba49716889ef6e50e1575f535e905bd8d9755d7..fcbe55d31b6b069a8a4740f7a3c3ca8e345f009b 100644
--- a/cc/test/fake_output_surface.cc
+++ b/cc/test/fake_output_surface.cc
@@ -147,6 +147,10 @@ bool FakeOutputSurface::SurfaceIsSuspendForRecycle() const {
   return suspended_for_recycle_;
 }
 
+unsigned FakeOutputSurface::GetOverlayTextureId() const {
+  return 10000;
+}
+
 void FakeOutputSurface::SetMemoryPolicyToSetAtBind(
     scoped_ptr<ManagedMemoryPolicy> memory_policy_to_set_at_bind) {
   memory_policy_to_set_at_bind_.swap(memory_policy_to_set_at_bind);