Associate audio streams with their source/destination RenderView.

content/renderer/media/renderer_webaudiodevice_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.
 
 #include "content/renderer/media/renderer_webaudiodevice_impl.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "content/renderer/media/audio_device_factory.h"
+#include "content/renderer/media/renderer_audio_output_device.h"
+#include "content/renderer/render_view_impl.h"
 #include "media/base/media_switches.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 
 using WebKit::WebAudioDevice;
+using WebKit::WebFrame;
 using WebKit::WebVector;
+using WebKit::WebView;
 
 namespace content {
 
 RendererWebAudioDeviceImpl::RendererWebAudioDeviceImpl(
     const media::AudioParameters& params,
     WebAudioDevice::RenderCallback* callback)
     : is_running_(false),
       client_callback_(callback) {
   audio_device_ = AudioDeviceFactory::NewOutputDevice();
 
   // TODO(crogers): remove once we properly handle input device selection.
   // https://code.google.com/p/chromium/issues/detail?id=147327
   if (CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kEnableWebAudioInput)) {
     // TODO(crogers): support more than hard-coded stereo:
     // https://code.google.com/p/chromium/issues/detail?id=147326
     audio_device_->InitializeIO(params, 2, this);
   } else {
     audio_device_->Initialize(params, this);
   }
 }
 
 RendererWebAudioDeviceImpl::~RendererWebAudioDeviceImpl() {
   stop();
 }
 
 void RendererWebAudioDeviceImpl::start() {
-  if (!is_running_) {
-    audio_device_->Start();
-    is_running_ = true;
+  if (is_running_)

[tommi (sloooow) - chröme, 2012/11/30 06:51:31]

I don't see any thread checks in this file, yet the class looks like it's single
threaded. Can I bug you to add 'not thread safe' checks?

[miu, 2012/12/01 00:40:17]

Done.  I left thread-checking out of Render/RenderIO since they don't mutate the
state of RendererWebAudioDeviceImpl.

+    return;
+
+  // Assumption: This method is being invoked within a V8 call stack.  CHECKs
+  // will fail in the call to frameForCurrentContext() otherwise.
+  //
+  // Therefore, we can perform look-ups to determine which RenderView is
+  // starting the audio device.  The reason for all this is because the creator
+  // of the WebAudio objects might not be the actual source of the audio (e.g.,
+  // an extension creates a object that is passed and used within a page).
+  WebFrame* const web_frame = WebFrame::frameForCurrentContext();
+  WebView* const web_view = web_frame ? web_frame->view() : NULL;
+  RenderViewImpl* const render_view =
+      web_view ? RenderViewImpl::FromWebView(web_view) : NULL;
+  if (render_view) {
+    audio_device_->SetSourceRenderView(render_view->routing_id());
   }
+
+  audio_device_->Start();
+  is_running_ = true;
 }
 
 void RendererWebAudioDeviceImpl::stop() {
   if (is_running_) {
     audio_device_->Stop();
     is_running_ = false;
   }
 }
 
 double RendererWebAudioDeviceImpl::sampleRate() {
@@ skipping 29 matching lines @@
                              web_audio_data,
                              dest->frames());
   }
 }
 
 void RendererWebAudioDeviceImpl::OnRenderError() {
   // TODO(crogers): implement error handling.
 }
 
 }  // namespace content