Reland review 34393006: Refactor MediaStreamManager to not output real device id.

media/video/capture/fake_video_capture_device.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.
 
 // Implementation of a fake VideoCaptureDevice class. Used for testing other
 // video capture classes when no real hardware is available.
 
 #ifndef MEDIA_VIDEO_CAPTURE_FAKE_VIDEO_CAPTURE_DEVICE_H_
 #define MEDIA_VIDEO_CAPTURE_FAKE_VIDEO_CAPTURE_DEVICE_H_
 
 #include <string>
 
+#include "base/atomicops.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/thread.h"
 #include "media/video/capture/video_capture_device.h"
 
 namespace media {
 
 class MEDIA_EXPORT FakeVideoCaptureDevice : public VideoCaptureDevice {
  public:
   static VideoCaptureDevice* Create(const Name& device_name);
   virtual ~FakeVideoCaptureDevice();
   // Used for testing. This will make sure the next call to Create will
   // return NULL;
   static void SetFailNextCreate();
+  static void SetNumberOfFakeDevices(size_t number_of_devices);
 
   static void GetDeviceNames(Names* device_names);
   static void GetDeviceSupportedFormats(const Name& device,
                                         VideoCaptureCapabilities* formats);
 
   // VideoCaptureDevice implementation.
   virtual void AllocateAndStart(const VideoCaptureParams& params,
                                 scoped_ptr<VideoCaptureDevice::Client> client)
       OVERRIDE;
   virtual void StopAndDeAllocate() OVERRIDE;
@@ skipping 21 matching lines @@
   scoped_ptr<uint8[]> fake_frame_;
   int frame_count_;
   VideoCaptureFormat capture_format_;
 
   // When the device is configured as mutating video captures, this vector
   // holds the available ones which are used in sequence, restarting at the end.
   std::vector<VideoCaptureFormat> format_roster_;
   int format_roster_index_;
 
   static bool fail_next_create_;
+  // |number_of_devices_| is atomic since tests can call SetNumberOfFakeDevices
+  // on the IO thread to set |number_of_devices_|. The variable can be
+  // read from a separate thread.
+  // TODO(perkj): Make tests independent of global state. crbug/323913
+  static base::subtle::Atomic32 number_of_devices_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeVideoCaptureDevice);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_VIDEO_CAPTURE_FAKE_VIDEO_CAPTURE_DEVICE_H_