Make Callback::Reset() return a copy to support use-cases where Run() ends up modifying |*this|.

media/filters/audio_renderer_base.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/filters/audio_renderer_base.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
 #include "base/callback.h"
+#include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "media/base/filter_host.h"
 
 namespace media {
 
 AudioRendererBase::AudioRendererBase()
     : state_(kUninitialized),
       pending_read_(false),
       received_end_of_stream_(false),
       rendered_end_of_stream_(false),
@@ skipping 147 matching lines @@
   }
 
   switch (state_) {
     case kUninitialized:
       NOTREACHED();
       return;
     case kPaused:
       if (buffer && !buffer->IsEndOfStream())
         algorithm_->EnqueueBuffer(buffer);
       DCHECK(!pending_read_);
-      ResetAndRunCB(&pause_cb_);
+      base::ResetAndReturn(&pause_cb_).Run();
       return;
     case kSeeking:
       if (IsBeforeSeekTime(buffer)) {
         ScheduleRead_Locked();
         return;
       }
       if (buffer && !buffer->IsEndOfStream()) {
         algorithm_->EnqueueBuffer(buffer);
         if (!algorithm_->IsQueueFull())
           return;
       }
       state_ = kPaused;
-      ResetAndRunCB(&seek_cb_, PIPELINE_OK);
+      base::ResetAndReturn(&seek_cb_).Run(PIPELINE_OK);
       return;
     case kPlaying:
     case kUnderflow:
     case kRebuffering:
       if (buffer && !buffer->IsEndOfStream())
         algorithm_->EnqueueBuffer(buffer);
       return;
     case kStopped:
       return;
   }
@@ skipping 100 matching lines @@
   base::AutoLock auto_lock(lock_);
   return algorithm_->playback_rate();
 }
 
 bool AudioRendererBase::IsBeforeSeekTime(const scoped_refptr<Buffer>& buffer) {
   return (state_ == kSeeking) && buffer && !buffer->IsEndOfStream() &&
       (buffer->GetTimestamp() + buffer->GetDuration()) < seek_timestamp_;
 }
 
 }  // namespace media