Add hints for potential overlay promotion on android.

components/display_compositor/compositor_overlay_candidate_validator_android.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/display_compositor/compositor_overlay_candidate_validator_android.h"
 
 #include <memory>
 
 #include "base/memory/ptr_util.h"
 #include "cc/output/overlay_processor.h"
@@ skipping 16 matching lines @@
 void CompositorOverlayCandidateValidatorAndroid::CheckOverlaySupport(
     cc::OverlayCandidateList* candidates) {
   // There should only be at most a single overlay candidate: the video quad.
   // There's no check that the presented candidate is really a video frame for
   // a fullscreen video. Instead it's assumed that if a quad is marked as
   // overlayable, it's a fullscreen video quad.
   DCHECK_LE(candidates->size(), 1u);
 
   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;
     candidate.plane_z_order = -1;
   }
 }
 
 bool CompositorOverlayCandidateValidatorAndroid::AllowCALayerOverlays() {
   return false;
 }
 
 // Overlays will still be allowed when software mirroring is enabled, even
 // though they won't appear in the mirror.
 void CompositorOverlayCandidateValidatorAndroid::SetSoftwareMirrorMode(
     bool enabled) {}
 
 }  // namespace display_compositor