Reland: Use a shared thread for media operations (round 3).

media/base/pipeline.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 "media/base/pipeline.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 616 matching lines @@
   video_renderer_.reset();
   demuxer_ = NULL;
 
   // If we stop during initialization/seeking we want to run |seek_cb_|
   // followed by |stop_cb_| so we don't leave outstanding callbacks around.
   if (!seek_cb_.is_null()) {
     base::ResetAndReturn(&seek_cb_).Run(status_);
     error_cb_.Reset();
   }
   if (!stop_cb_.is_null()) {
+    error_cb_.Reset();
     base::ResetAndReturn(&stop_cb_).Run();
-    error_cb_.Reset();
+
+    // NOTE: pipeline may be deleted at this point in time as a result of
+    // executing |stop_cb_|.
+    return;
   }
   if (!error_cb_.is_null()) {
     DCHECK_NE(status_, PIPELINE_OK);
     base::ResetAndReturn(&error_cb_).Run(status_);
   }
 }
 
 void Pipeline::AddBufferedByteRange(int64 start, int64 end) {
   DCHECK(IsRunning());
   base::AutoLock auto_lock(lock_);
@@ skipping 285 matching lines @@
 void Pipeline::StartClockIfWaitingForTimeUpdate_Locked() {
   lock_.AssertAcquired();
   if (!waiting_for_clock_update_)
     return;
 
   waiting_for_clock_update_ = false;
   clock_->Play();
 }
 
 }  // namespace media