Fixing flakiness of TextureLayerChangeInvisibleMailboxTest

cc/trees/proxy_impl.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 "cc/trees/proxy_impl.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/auto_reset.h"
@@ skipping 104 matching lines @@
 void ProxyImpl::UpdateBrowserControlsStateOnImpl(
     BrowserControlsState constraints,
     BrowserControlsState current,
     bool animate) {
   DCHECK(IsImplThread());
   layer_tree_host_impl_->browser_controls_manager()->UpdateBrowserControlsState(
       constraints, current, animate);
 }
 
 void ProxyImpl::InitializeCompositorFrameSinkOnImpl(
-    CompositorFrameSink* compositor_frame_sink) {
+    CompositorFrameSink* compositor_frame_sink,
+    base::WeakPtr<ProxyMain> compositor_frame_sink_weak_ptr) {

[danakj, 2017/04/05 16:08:49]

If you want, and I think it'd be slightly simpler, you could make the weakptrs
entirely in proxy_impl, because
- ReleaseCompositorFrameSink() is a synchronous method to the compositor thread,
so the main thread can't run the callback while telling the compositor thread to
release.
- DidLoseCompositorFrameSink comes from the compositor thread.

You'd do it by putting the factory right on proxy_impl, and invalidating inside
this class.

   TRACE_EVENT0("cc", "ProxyImpl::InitializeCompositorFrameSinkOnImplThread");
   DCHECK(IsImplThread());
 
+  compositor_frame_sink_weak_ptr_ = compositor_frame_sink_weak_ptr;
+
   LayerTreeHostImpl* host_impl = layer_tree_host_impl_.get();
   bool success = host_impl->InitializeRenderer(compositor_frame_sink);
   MainThreadTaskRunner()->PostTask(
       FROM_HERE, base::Bind(&ProxyMain::DidInitializeCompositorFrameSink,
                             proxy_main_weak_ptr_, success));
   if (success)
     scheduler_->DidCreateAndInitializeCompositorFrameSink();
 }
 
 void ProxyImpl::MainThreadHasStoppedFlingingOnImpl() {
@@ skipping 135 matching lines @@
   }
 }
 
 void ProxyImpl::DidReceiveCompositorFrameAckOnImplThread() {
   TRACE_EVENT0("cc,benchmark",
                "ProxyImpl::DidReceiveCompositorFrameAckOnImplThread");
   DCHECK(IsImplThread());
   scheduler_->DidReceiveCompositorFrameAck();
   MainThreadTaskRunner()->PostTask(
       FROM_HERE, base::Bind(&ProxyMain::DidReceiveCompositorFrameAck,
-                            proxy_main_weak_ptr_));
+                            compositor_frame_sink_weak_ptr_));
 }
 
 void ProxyImpl::OnCanDrawStateChanged(bool can_draw) {
   TRACE_EVENT1("cc", "ProxyImpl::OnCanDrawStateChanged", "can_draw", can_draw);
   DCHECK(IsImplThread());
   scheduler_->SetCanDraw(can_draw);
 }
 
 void ProxyImpl::NotifyReadyToActivate() {
   TRACE_EVENT0("cc", "ProxyImpl::NotifyReadyToActivate");
@@ skipping 354 matching lines @@
 ProxyImpl::BlockedMainCommitOnly& ProxyImpl::blocked_main_commit() {
   DCHECK(IsMainThreadBlocked() && commit_completion_event_);
   return main_thread_blocked_commit_vars_unsafe_;
 }
 
 base::SingleThreadTaskRunner* ProxyImpl::MainThreadTaskRunner() {
   return task_runner_provider_->MainThreadTaskRunner();
 }
 
 }  // namespace cc