Fixing flakiness of TextureLayerChangeInvisibleMailboxTest

content/browser/renderer_host/compositor_impl_android.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/compositor_impl_android.h"
 
 #include <android/bitmap.h>
 #include <android/native_window_jni.h>
 #include <stdint.h>
 #include <unordered_set>
@@ skipping 788 matching lines @@
   return gpu_capabilities_.texture_format_etc1_npot;
 }
 
 void CompositorImpl::DidSubmitCompositorFrame() {
   TRACE_EVENT0("compositor", "CompositorImpl::DidSubmitCompositorFrame");
   pending_frames_++;
 }
 
 void CompositorImpl::DidReceiveCompositorFrameAck() {
   TRACE_EVENT0("compositor", "CompositorImpl::DidReceiveCompositorFrameAck");
+  if (!has_compositor_frame_sink_)

[danakj, 2017/04/04 22:14:47]

This would be racey if CompositorImpl can has_compositor_frame_sink_ again
before the ack arrives, which is why I suggested the weakptrfactory to cancel
the callback mid-flight. But maybe you can convince us that that wouldn't
happen?

[Saman Sami, 2017/04/04 22:23:47]

Interesting. No, it's not obvious to me why it won't be racey. I'll implement
this tomorrow.

+    return;
   DCHECK_GT(pending_frames_, 0U);
   pending_frames_--;
   client_->DidSwapFrame(pending_frames_);
 }
 
 void CompositorImpl::DidLoseCompositorFrameSink() {
   TRACE_EVENT0("compositor", "CompositorImpl::DidLoseCompositorFrameSink");
   has_compositor_frame_sink_ = false;
   client_->DidSwapFrame(0);
 }
@@ skipping 42 matching lines @@
   }
   GetSurfaceManager()->UnregisterFrameSinkHierarchy(frame_sink_id_,
                                                     frame_sink_id);
 }
 
 bool CompositorImpl::HavePendingReadbacks() {
   return !readback_layer_tree_->children().empty();
 }
 
 }  // namespace content