Add support for switching the audio output device for HTMLMediaElements.

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 6637719b0a6980ec34b324f9a75c52454e0c8d27..0770d70ba6e439294fffbe3bdee0d26a9f4e600a 100644
--- a/media/blink/webaudiosourceprovider_impl.cc
+++ b/media/blink/webaudiosourceprovider_impl.cc
@@ -163,6 +163,15 @@ bool WebAudioSourceProviderImpl::SetVolume(double volume) {
   return true;
 }
 
+void WebAudioSourceProviderImpl::SwitchOutputDevice(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const base::Callback<void(int)>& callback) {
+  base::AutoLock auto_lock(sink_lock_);
+  if (!client_)
+    sink_->SwitchOutputDevice(device_id, security_origin, callback);
+}
+
 void WebAudioSourceProviderImpl::Initialize(
     const AudioParameters& params,
     RenderCallback* renderer) {