Plumb audio focus support for spitzer clients.

media/blink/webaudiosourceprovider_impl.cc

Index: media/blink/webaudiosourceprovider_impl.cc
diff --git a/media/blink/webaudiosourceprovider_impl.cc b/media/blink/webaudiosourceprovider_impl.cc
index 5b70a3091ba7760878c7f5d9f80147af4a1292c6..8f74ab237f0f511223f4b4a67a36fa210f2f7883 100644
--- a/media/blink/webaudiosourceprovider_impl.cc
+++ b/media/blink/webaudiosourceprovider_impl.cc
@@ -56,6 +56,7 @@ WebAudioSourceProviderImpl::WebAudioSourceProviderImpl(
       renderer_(NULL),
       client_(NULL),
       sink_(sink),
+      enable_audio_focus_(false),
       weak_factory_(this) {}
 
 WebAudioSourceProviderImpl::~WebAudioSourceProviderImpl() {
@@ -177,7 +178,14 @@ void WebAudioSourceProviderImpl::Initialize(
   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();