Add a method to tab_utils.h to find out whether a tab is playing audio.

content/browser/renderer_host/render_process_host_impl.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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 498 matching lines @@
       storage_partition_impl_->GetAppCacheService(),
       ChromeBlobStorageContext::GetFor(browser_context),
       new RendererURLRequestContextSelector(browser_context, GetID()));
 
   channel_->AddFilter(resource_message_filter);
   media::AudioManager* audio_manager = BrowserMainLoop::GetAudioManager();
   MediaStreamManager* media_stream_manager =
       BrowserMainLoop::GetMediaStreamManager();
   channel_->AddFilter(new AudioInputRendererHost(audio_manager,
                                                  media_stream_manager));
-  channel_->AddFilter(new AudioRendererHost(audio_manager, media_observer));
+  channel_->AddFilter(new AudioRendererHost(GetID(), audio_manager,
+                                            media_observer));
   channel_->AddFilter(new VideoCaptureHost());
   channel_->AddFilter(new AppCacheDispatcherHost(
       storage_partition_impl_->GetAppCacheService(),
       GetID()));
   channel_->AddFilter(new ClipboardMessageFilter());
   channel_->AddFilter(
       new DOMStorageMessageFilter(
           GetID(),
           storage_partition_impl_->GetDOMStorageContext()));
   channel_->AddFilter(
@@ skipping 1064 matching lines @@
                "RenderWidgetHostImpl::OnCompositorSurfaceBuffersSwappedNoHost");
   AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
   ack_params.surface_handle = surface_handle;
   ack_params.sync_point = 0;
   RenderWidgetHostImpl::AcknowledgeBufferPresent(route_id,
                                                  gpu_process_host_id,
                                                  ack_params);
 }
 
 }  // namespace content