Wait for encode thread during VideoScheduler teardown.

remoting/host/video_scheduler.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 "remoting/host/video_scheduler.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 158 matching lines @@
 void VideoScheduler::StopOnCaptureThread(const base::Closure& done_task) {
   DCHECK(capture_task_runner_->BelongsToCurrentThread());
 
   // Stop |capturer_| and clear it to prevent pending tasks from using it.
   capturer_->Stop();
   capturer_ = NULL;
 
   // |capture_timer_| must be destroyed on the thread on which it is used.
   capture_timer_.reset();
 
-  // Activity on the encode thread will stop implicitly as a result of
-  // captures having stopped.
-  network_task_runner_->PostTask(FROM_HERE, done_task);
+  // Ensure that the encode thread is no longer processing capture data,
+  // otherwise tearing down |capturer_| will crash it.  See crbug.com/163641.
+  // TODO(wez): Make it safe to tear down capturer while buffers remain, and
+  // remove this work-around.
+  capture_task_runner_->PostTask(FROM_HERE,
+      base::Bind(&VideoScheduler::StopOnEncodeThread, this, done_task));
 }
 
 void VideoScheduler::ScheduleNextCapture() {
   DCHECK(capture_task_runner_->BelongsToCurrentThread());
 
   capture_timer_->Start(FROM_HERE,
                         scheduler_.NextCaptureDelay(),
                         this,
                         &VideoScheduler::CaptureNextFrame);
 }
@@ skipping 103 matching lines @@
   if (last) {
     scheduler_.RecordEncodeTime(
         base::TimeDelta::FromMilliseconds(packet->encode_time_ms()));
   }
 
   network_task_runner_->PostTask(
       FROM_HERE, base::Bind(&VideoScheduler::SendVideoPacket, this,
                             base::Passed(&packet)));
 }
 
+void VideoScheduler::StopOnEncodeThread(const base::Closure& done_task) {
+  DCHECK(encode_task_runner_->BelongsToCurrentThread());
+
+  // This is posted by StopOnCaptureThread, so we know that by the time we
+  // process it there are no more encode tasks queued.
+  network_task_runner_->PostTask(FROM_HERE, done_task);
+}
+
 }  // namespace remoting