Add TestBrowserThreadBundle into RenderViewHostTestHarness. Kill some unnecessary real threads.

chrome/browser/media/media_capture_devices_dispatcher.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 "chrome/browser/media/media_capture_devices_dispatcher.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/prefs/pref_service.h"
 #include "base/sha1.h"
@@ skipping 68 matching lines @@
 }
 
 }  // namespace
 
 MediaCaptureDevicesDispatcher* MediaCaptureDevicesDispatcher::GetInstance() {
   return Singleton<MediaCaptureDevicesDispatcher>::get();
 }
 
 MediaCaptureDevicesDispatcher::MediaCaptureDevicesDispatcher()
     : devices_enumerated_(false),
+      is_device_enumeration_disabled_(false),
       media_stream_capture_indicator_(new MediaStreamCaptureIndicator()),
       audio_stream_indicator_(new AudioStreamIndicator()) {}
 
 MediaCaptureDevicesDispatcher::~MediaCaptureDevicesDispatcher() {}
 
 void MediaCaptureDevicesDispatcher::RegisterUserPrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterStringPref(
       prefs::kDefaultAudioCaptureDevice,
       std::string(),
@@ skipping 11 matching lines @@
 }
 
 void MediaCaptureDevicesDispatcher::RemoveObserver(Observer* observer) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   observers_.RemoveObserver(observer);
 }
 
 const MediaStreamDevices&
 MediaCaptureDevicesDispatcher::GetAudioCaptureDevices() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!devices_enumerated_) {
+  if (!is_device_enumeration_disabled_ && !devices_enumerated_) {
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(&content::EnsureMonitorCaptureDevices));
     devices_enumerated_ = true;
   }
   return audio_devices_;
 }
 
 const MediaStreamDevices&
 MediaCaptureDevicesDispatcher::GetVideoCaptureDevices() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!devices_enumerated_) {
+  if (!is_device_enumeration_disabled_ && !devices_enumerated_) {
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(&content::EnsureMonitorCaptureDevices));
     devices_enumerated_ = true;
   }
   return video_devices_;
 }
 
 void MediaCaptureDevicesDispatcher::ProcessMediaAccessRequest(
     content::WebContents* web_contents,
@@ skipping 154 matching lines @@
   }
   if (video) {
     const content::MediaStreamDevices& video_devices = GetVideoCaptureDevices();
     const content::MediaStreamDevice* const device =
         FindDefaultDeviceWithId(video_devices, requested_device_id);
     if (device)
       devices->push_back(*device);
   }
 }
 
+void MediaCaptureDevicesDispatcher::DisableDeviceEnumerationForTesting() {
+  is_device_enumeration_disabled_ = true;
+}
+
 scoped_refptr<MediaStreamCaptureIndicator>
     MediaCaptureDevicesDispatcher::GetMediaStreamCaptureIndicator() {
   return media_stream_capture_indicator_;
 }
 
 scoped_refptr<AudioStreamIndicator>
 MediaCaptureDevicesDispatcher::GetAudioStreamIndicator() {
   return audio_stream_indicator_;
 }
 
@@ skipping 61 matching lines @@
     int render_process_id,
     int render_view_id,
     const content::MediaStreamDevice& device,
     content::MediaRequestState state) {
   FOR_EACH_OBSERVER(Observer, observers_,
                     OnRequestUpdate(render_process_id,
                                     render_view_id,
                                     device,
                                     state));
 }