Refactor how the DeviceMonitor is started.

content/browser/media/media_devices_monitor.cc

 // 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.
 
 #include "content/public/browser/media_devices_monitor.h"
 
 #include "content/browser/browser_main_loop.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 namespace {
 void EnsureMonitorCaptureDevicesInternal(
     MediaStreamManager* media_stream_manager) {
-  // TODO(perkj): The argument list suggests that this is the wrong design. Can
-  // we add a separate method for device monitoring?
-  media_stream_manager->EnumerateDevices(
-      NULL, -1, -1, NULL, -1, MEDIA_DEVICE_AUDIO_CAPTURE, GURL());
+  media_stream_manager->StartMonitoring();

[no longer working on chromium, 2013/11/04 15:51:22]

This EnsureMonitorCaptureDevicesInternal is triggered event time there is a
device change event, the naming of StartMonitoring() indicates that it is wrong
to start monitoring multiple times.
Can you just add a interface called EnsureMonitoring() to the MSM and move
Startmonitoring() back to its private method?

 }
 }
 
 void EnsureMonitorCaptureDevices() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&EnsureMonitorCaptureDevicesInternal,
                  BrowserMainLoop::GetInstance()->media_stream_manager()));
 }
 
 }  // namespace content