Fix incomplete teardown of demuxer.

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 1119 matching lines @@
       url_, base::Bind(&Pipeline::OnDemuxerBuilt, this));
 }
 
 void Pipeline::OnDemuxerBuilt(PipelineStatus status, Demuxer* demuxer) {
   if (MessageLoop::current() != message_loop_) {
     message_loop_->PostTask(FROM_HERE, base::Bind(
         &Pipeline::OnDemuxerBuilt, this, status, make_scoped_refptr(demuxer)));
     return;
   }
 
+  demuxer_ = demuxer;
   if (status != PIPELINE_OK) {
     SetError(status);
     return;
   }
 
-  if (!demuxer) {
-    SetError(PIPELINE_ERROR_REQUIRED_FILTER_MISSING);
-    return;
-  }
-
-  demuxer_ = demuxer;
+  CHECK(demuxer_) << "Null demuxer encountered despite PIPELINE_OK.";
   demuxer_->set_host(this);
 
   {
     base::AutoLock auto_lock(lock_);
     // We do not want to start the clock running. We only want to set the base
     // media time so our timestamp calculations will be correct.
     clock_->SetTime(demuxer_->GetStartTime(), demuxer_->GetStartTime());
   }
 
   OnFilterInitialize(PIPELINE_OK);
@@ skipping 264 matching lines @@
 void Pipeline::StartClockIfWaitingForTimeUpdate_Locked() {
   lock_.AssertAcquired();
   if (!waiting_for_clock_update_)
     return;
 
   waiting_for_clock_update_ = false;
   clock_->Play();
 }
 
 }  // namespace media