exo::CompositorFrameSinkHolder's release callbacks hold ref

components/exo/compositor_frame_sink_holder.cc

Index: components/exo/compositor_frame_sink_holder.cc
diff --git a/components/exo/compositor_frame_sink_holder.cc b/components/exo/compositor_frame_sink_holder.cc
index dd82aff4dc1dc915afc79434ccbb091dc0c6d476..d76986c9f05839446ecbe8ebe396501cce11794a 100644
--- a/components/exo/compositor_frame_sink_holder.cc
+++ b/components/exo/compositor_frame_sink_holder.cc
@@ -4,6 +4,7 @@
 
 #include "components/exo/compositor_frame_sink_holder.h"
 
+#include "base/callback_helpers.h"
 #include "cc/resources/returned_resource.h"
 #include "components/exo/surface.h"
 
@@ -32,7 +33,7 @@ bool CompositorFrameSinkHolder::HasReleaseCallbackForResource(
 void CompositorFrameSinkHolder::AddResourceReleaseCallback(
     cc::ResourceId id,
     std::unique_ptr<cc::SingleReleaseCallback> callback) {
-  release_callbacks_[id] = std::make_pair(this, std::move(callback));
+  release_callbacks_[id] = std::move(callback);
 }
 
 void CompositorFrameSinkHolder::ActivateFrameCallbacks(
@@ -80,13 +81,14 @@ void CompositorFrameSinkHolder::OnBeginFrame(const cc::BeginFrameArgs& args) {
 
 void CompositorFrameSinkHolder::ReclaimResources(
     const cc::ReturnedResourceArray& resources) {
+  scoped_refptr<CompositorFrameSinkHolder> holder(this);

[reveman, 2016/12/21 20:05:42]

Please remove this and use PostTask instead. Instance being destroyed when a
member function is called is a bad pattern. Better to defer this I think.

[Alex Z., 2016/12/21 21:30:11]

Sorry about this. I forgot to remove the line after changing to
ScopedClosureRunner.

I noticed that after using ScopedClosureRunner, several GamepadTest became
flaky. I'll look into it.

   for (auto& resource : resources) {
     auto it = release_callbacks_.find(resource.id);
     DCHECK(it != release_callbacks_.end());
-    std::unique_ptr<cc::SingleReleaseCallback> callback =
-        std::move(it->second.second);
+    base::ScopedClosureRunner runner(base::Bind(
+        &cc::SingleReleaseCallback::Run, base::Passed(std::move(it->second)),
+        resource.sync_token, resource.lost));
     release_callbacks_.erase(it);
-    callback->Run(resource.sync_token, resource.lost);
   }
 }