cc: Dump scheduler and tile manager state when commit is blocked.

cc/trees/proxy_main.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_main.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/memory/ptr_util.h"
@@ skipping 247 matching lines @@
         task_runner_provider_->blocking_main_thread_task_runner());
 
     bool hold_commit_for_activation = commit_waits_for_activation_;
     commit_waits_for_activation_ = false;
     CompletionEvent completion;
     ImplThreadTaskRunner()->PostTask(
         FROM_HERE, base::Bind(&ProxyImpl::NotifyReadyToCommitOnImpl,
                               base::Unretained(proxy_impl_.get()), &completion,
                               layer_tree_host_, begin_main_frame_start_time,
                               hold_commit_for_activation));
-    completion.Wait();
+    // TODO(sunnyps): Remove this code once crbug.com/668892 is fixed.
+    // content/common/content_constants_internal.cc defines hung renderer delay
+    // as 30s so choose something less than that but still sufficiently long.
+    constexpr base::TimeDelta kDumpDelay = base::TimeDelta::FromSeconds(20);

[vmpstr, 2017/04/11 01:06:46]

nit: static?

[sunnyps, 2017/04/11 18:22:48]

Done.

+    if (!completion.TimedWait(kDumpDelay)) {
+      ImplThreadTaskRunner()->PostTask(
+          FROM_HERE, base::Bind(&ProxyImpl::DumpForBeginMainFrameHang,
+                                base::Unretained(proxy_impl_.get())));
+      completion.Wait();

[vmpstr, 2017/04/11 01:06:46]

nit: this will DCHECK since we've already waited. Maybe only set waited = true
if we didn't time out in the completion event?

[sunnyps, 2017/04/11 18:22:48]

Changed TimedWait to set waited_ to false if wait failed.

+    }
   }
 
   current_pipeline_stage_ = NO_PIPELINE_STAGE;
   layer_tree_host_->CommitComplete();
   layer_tree_host_->DidBeginMainFrame();
 }
 
 bool ProxyMain::IsStarted() const {
   DCHECK(IsMainThread());
   return started_;
@@ skipping 226 matching lines @@
 
 bool ProxyMain::IsImplThread() const {
   return task_runner_provider_->IsImplThread();
 }
 
 base::SingleThreadTaskRunner* ProxyMain::ImplThreadTaskRunner() {
   return task_runner_provider_->ImplThreadTaskRunner();
 }
 
 }  // namespace cc