Plumb audio focus support for spitzer clients.

media/blink/webaudiosourceprovider_impl.cc

 // Copyright 2013 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/blink/webaudiosourceprovider_impl.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 38 matching lines @@
 
 WebAudioSourceProviderImpl::WebAudioSourceProviderImpl(
     const scoped_refptr<RestartableAudioRendererSink>& sink)
     : channels_(0),
       sample_rate_(0),
       volume_(1.0),
       state_(kStopped),
       renderer_(NULL),
       client_(NULL),
       sink_(sink),
+      enable_audio_focus_(false),
       weak_factory_(this) {}
 
 WebAudioSourceProviderImpl::~WebAudioSourceProviderImpl() {
 }
 
 void WebAudioSourceProviderImpl::setClient(
     blink::WebAudioSourceProviderClient* client) {
   base::AutoLock auto_lock(sink_lock_);
   if (client && client != client_) {
     // Detach the audio renderer from normal playback.
@@ skipping 101 matching lines @@
   return sink_->GetOutputDevice();
 }
 
 void WebAudioSourceProviderImpl::Initialize(
     const AudioParameters& params,
     RenderCallback* renderer) {
   base::AutoLock auto_lock(sink_lock_);
   renderer_ = renderer;
 
   DCHECK_EQ(state_, kStopped);
-  sink_->Initialize(params, renderer);
+
+  if (enable_audio_focus_) {
+    AudioParameters new_params = params;
+    new_params.set_effects(params.effects() | AudioParameters::FOCUSABLE);
+    sink_->Initialize(new_params, renderer);
+  } else {
+    sink_->Initialize(params, renderer);
+  }
 
   // Keep track of the format in case the client hasn't yet been set.
   channels_ = params.channels();
   sample_rate_ = params.sample_rate();
 
   if (!set_format_cb_.is_null())
     base::ResetAndReturn(&set_format_cb_).Run();
 }
 
 void WebAudioSourceProviderImpl::OnSetFormat() {
   base::AutoLock auto_lock(sink_lock_);
   if (!client_)
     return;
 
   // Inform Blink about the audio stream format.
   client_->setFormat(channels_, sample_rate_);
 }
 
 }  // namespace media