Fix webrtcAudioPrivate API to handle requests from <webview>s.

chrome/common/extensions/api/webrtc_audio_private.idl

 // 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.
 
 // The <code>chrome.webrtcAudioPrivate</code> API allows enumeration
 // of audio output (sink) devices as well as getting and setting the
-// active device for a given tab.
+// active device for a given requesting process.
 //
 // Note that device IDs as used in this API are opaque (i.e. they are
 // not the hardware identifier of the device) and while they are
 // unique and persistent across sessions, they are valid only to the
 // extension calling this API (i.e. they cannot be shared between
 // extensions).
 //
 // See http://goo.gl/8rOmgk for further documentation of this API.
 
 namespace webrtcAudioPrivate {
@@ skipping 16 matching lines @@
     boolean isReady;
     // True if this device is the default audio sink device on the
     // machine.
     boolean isDefault;
   };
 
   callback GetSinksCallback = void(SinkInfo[] sinkInfo);
   callback SinkIdCallback = void(DOMString sinkId);
   callback CompletionCallback = void();
 
+  dictionary RequestInfo {
+    // The tab identifier from the chrome.tabs API, if the request is from a
+    // tab.
+    long? tabId;
+    // The guest process id for the requester, if the request is from a
+    // webview.
+    long? guestProcessId;
+  };
+
   interface Functions {
     // Retrieves a list of available audio sink devices.
     static void getSinks(GetSinksCallback callback);
 
-    // Retrieves the currently active audio sink for the given tab.
-    static void getActiveSink(long tabId,
+    // Retrieves the currently active audio sink for the given requesting
+    // process.
+    static void getActiveSink(RequestInfo request,
                               SinkIdCallback callback);
 
-    // Sets the active audio sink device for the specified tab.
-    static void setActiveSink(long tabId,
+    // Sets the active audio sink device for the specified requesting process.
+    static void setActiveSink(RequestInfo request,
                               DOMString sinkId,
                               optional CompletionCallback callback);
 
     // Given a security origin and an input device ID valid for that
     // security origin, retrieve an audio sink ID valid for the
     // extension, or the empty string if there is no associated audio
     // sink.
     //
     // The associated sink ID can be used as a sink ID for
-    // setActiveSink. It is valid irrespective of which tab you are
+    // setActiveSink. It is valid irrespective of which process you are
     // setting the active sink for.
     static void getAssociatedSink(DOMString securityOrigin,
                                   DOMString sourceIdInOrigin,
                                   SinkIdCallback cb);
   };
 
   interface Events {
     // Fired when audio sink devices are added or removed.
     static void onSinksChanged();
   };
 };