Mac Video Capture Device: split VCD into VCD and Factory.

media/base/media_switches.cc

Index: media/base/media_switches.cc
diff --git a/media/base/media_switches.cc b/media/base/media_switches.cc
index 515c0bc3d1af45fbebbfc629d9ca60886c88dedb..886b9202a221f9f726c49841615aa111588ce66d 100644
--- a/media/base/media_switches.cc
+++ b/media/base/media_switches.cc
@@ -40,6 +40,7 @@ const char kAlsaOutputDevice[] = "alsa-output-device";
 // for experimentation purposes, in particular library load time issue, the
 // usage of this library can be enabled by using this flag.
 const char kEnableAVFoundation[] = "enable-avfoundation";
+
 // QTKit is the media capture API predecessor to AVFoundation, available up and
 // until Mac OS X 10.9 (despite being deprecated in this last one). This flag
 // is used for troubleshooting and testing, and forces QTKit in builds and
@@ -85,6 +86,10 @@ const char kWaveOutBuffers[] = "waveout-buffers";
 const char kUseCras[] = "use-cras";
 #endif
 
+// Use fake device for Media Stream to replace actual camera and microphone. The
+// video part is actually used in VideoCaptureDeviceFactory.
+const char kUseFakeDeviceForMediaStream[] = "use-fake-device-for-media-stream";
+
 // Use a raw video file as fake video capture device.
 const char kUseFileForFakeVideoCapture[] = "use-file-for-fake-video-capture";