Initialize default audio device ID with explicit device ID.

content/browser/renderer_host/media/media_stream_manager.h

 // 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.
 
 // MediaStreamManager is used to open media capture devices (video supported
 // now). Call flow:
 // 1. GenerateStream is called when a render process wants to use a capture
 //    device.
 // 2. MediaStreamManager will ask MediaStreamUIController for permission to
 //    use devices and for which device to use.
@@ skipping 349 matching lines @@
                                   const MediaStreamDevices& devices);
   void HandleCheckMediaAccessResponse(const std::string& label,
                                       bool have_access);
 
   // Picks a device ID from a list of required and alternate device IDs,
   // presented as part of a TrackControls structure.
   // Either the required device ID is picked (if present), or the first
   // valid alternate device ID.
   // Returns false if the required device ID is present and invalid.
   // Otherwise, if no valid device is found, device_id is unchanged.
-  bool PickDeviceId(const std::string& salt,
+  bool PickDeviceId(MediaStreamType type,
+                    const std::string& salt,
                     const url::Origin& security_origin,
                     const TrackControls& controls,
                     const MediaDeviceInfoArray& devices,
                     std::string* device_id) const;
 
   // Finds the requested device id from request. The requested device type
   // must be MEDIA_DEVICE_AUDIO_CAPTURE or MEDIA_DEVICE_VIDEO_CAPTURE.
   bool GetRequestedDeviceCaptureId(const DeviceRequest* request,
                                    MediaStreamType type,
                                    const MediaDeviceInfoArray& devices,
@@ skipping 45 matching lines @@
   std::map<int, base::Callback<void(const std::string&)>> log_callbacks_;
 
   GenerateStreamTestCallback generate_stream_test_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MEDIA_STREAM_MANAGER_H_