Add hints for potential overlay promotion on android.

cc/output/overlay_candidate.h

Index: cc/output/overlay_candidate.h
diff --git a/cc/output/overlay_candidate.h b/cc/output/overlay_candidate.h
index 7ced45c4f1b9b3f3595de974a6f1d1205d1822cb..b447e80db39e689b81afa19cee183345ecfca07b 100644
--- a/cc/output/overlay_candidate.h
+++ b/cc/output/overlay_candidate.h
@@ -70,6 +70,14 @@ class CC_EXPORT OverlayCandidate {
   bool use_output_surface_for_resource;
   // Texture resource to present in an overlay.
   unsigned resource_id;
+
+#if defined(OS_ANDROID)
+  // For candidates from StreamVideoDrawQuads, this records whether the quad is
+  // marked as being backed by a SurfaceTexture or not.  If so, it's not really
+  // promotable to an overlay.
+  bool is_backed_by_surface_texture;
+#endif
+
   // Stacking order of the overlay plane relative to the main surface,
   // which is 0. Signed to allow for "underlays".
   int plane_z_order;