Add hints for potential overlay promotion on android.

components/display_compositor/compositor_overlay_candidate_validator_android.cc

Index: components/display_compositor/compositor_overlay_candidate_validator_android.cc
diff --git a/components/display_compositor/compositor_overlay_candidate_validator_android.cc b/components/display_compositor/compositor_overlay_candidate_validator_android.cc
index 805dae3b917d7147b70e749309e068ab3518483e..b5b1c13019bd63b5c2627cc4affa57348e7332d4 100644
--- a/components/display_compositor/compositor_overlay_candidate_validator_android.cc
+++ b/components/display_compositor/compositor_overlay_candidate_validator_android.cc
@@ -34,6 +34,17 @@ void CompositorOverlayCandidateValidatorAndroid::CheckOverlaySupport(
 
   if (!candidates->empty()) {
     cc::OverlayCandidate& candidate = candidates->front();
+
+    // This quad either will be promoted, or would be if it were backed by a
+    // SurfaceView.  Record that it should get a promotion hint.
+    candidates->promotable_resource_hints_.insert(candidate.resource_id);
+
+    if (candidate.is_backed_by_surface_texture) {
+      // This quad would be promoted if it were backed by a SurfaceView.  Since
+      // it isn't, we can't promote it.
+      return;
+    }
+
     candidate.display_rect =
         gfx::RectF(gfx::ToEnclosingRect(candidate.display_rect));
     candidate.overlay_handled = true;