Extract VideoCaptureDeviceFactory out of VideoCaptureDevice and use for File and FakeVCD.

content/browser/renderer_host/media/video_capture_manager.h

Index: content/browser/renderer_host/media/video_capture_manager.h
diff --git a/content/browser/renderer_host/media/video_capture_manager.h b/content/browser/renderer_host/media/video_capture_manager.h
index 35aee8eba235ef42c49b1fae80e37feb8b17652f..e259bbc50ff490365641dd58d15b839694998be8 100644
--- a/content/browser/renderer_host/media/video_capture_manager.h
+++ b/content/browser/renderer_host/media/video_capture_manager.h
@@ -24,6 +24,7 @@
 #include "content/common/content_export.h"
 #include "content/common/media/media_stream_options.h"
 #include "media/video/capture/video_capture_device.h"
+#include "media/video/capture/video_capture_device_factory.h"
 #include "media/video/capture/video_capture_types.h"
 
 namespace content {
@@ -55,7 +56,7 @@ class CONTENT_EXPORT VideoCaptureManager : public MediaStreamProvider {
   // Used by unit test to make sure a fake device is used instead of a real
   // video capture device. Due to timing requirements, the function must be
   // called before EnumerateDevices and Open.
-  void UseFakeDevice();
+  void UseFakeDevice(scoped_ptr<media::VideoCaptureDeviceFactory> factory);

[perkj_chrome, 2014/04/15 09:34:01]

Why not just inject the factory in the ctor? Tests can inject fake version and
production the real one. You can have two ctors if you want the default ctor to
always create the default implementation of the factory.

[mcasas, 2014/04/15 13:47:09]

Extended the ctor to accept a Factory. 
Some higher level UTs (MediaStreamDispatcherHostTest,
VideoCaptureHostTest, MediaStreamManagerTest), 
manipulate MediaStreamManager that in turn manages
VCM, they create the MSM which injects a "normal" factory
and later call UseFakeVideoDevice, which changes the
 factory to Fake/File. This is suboptimal. 

 
   // Called by VideoCaptureHost to locate a capture device for |capture_params|,
   // adding the Host as a client of the device's controller if successful. The
@@ -103,6 +104,11 @@ class CONTENT_EXPORT VideoCaptureManager : public MediaStreamProvider {
   void SetDesktopCaptureWindowId(media::VideoCaptureSessionId session_id,
                                  gfx::NativeViewId window_id);
 
+  // Gets a weak reference to the device factory, used for tests.
+  media::VideoCaptureDeviceFactory* video_capture_device_factory() const {
+    return video_capture_device_factory_.get();
+  }
+
  private:
   virtual ~VideoCaptureManager();
   struct DeviceEntry;
@@ -220,6 +226,8 @@ class CONTENT_EXPORT VideoCaptureManager : public MediaStreamProvider {
   typedef std::set<DeviceEntry*> DeviceEntries;
   DeviceEntries devices_;
 
+  scoped_ptr<media::VideoCaptureDeviceFactory> video_capture_device_factory_;
+
   // Local cache of the enumerated video capture devices' names and capture
   // supported formats. A snapshot of the current devices and their capabilities
   // is composed in GetAvailableDevicesInfoOnDeviceThread() --coming
@@ -229,15 +237,13 @@ class CONTENT_EXPORT VideoCaptureManager : public MediaStreamProvider {
   // active device capture format from the VideoCaptureController associated.
   DeviceInfos devices_info_cache_;
 
-  // For unit testing and for performance/quality tests, a test device can be
-  // used instead of a real one. The device can be a simple fake device (a
-  // rolling pacman), or a file that is played in a loop continuously. This only
-  // applies to the MEDIA_DEVICE_VIDEO_CAPTURE device type.
-  enum {
-    DISABLED,
-    TEST_PATTERN,
-    Y4M_FILE
-  } artificial_device_source_for_testing_;
+  // A test device can be used for unit testing and for performance/quality
+  // measurements. This device is usually injected from the test harness, but
+  // can also come from MediaStreamManager in normal operation, via command line
+  // flag. Supported test devices include a simple fake device (a rolling
+  // pacman), or a file that is played in a loop continuously. Test device is
+  // only and always of type MEDIA_DEVICE_VIDEO_CAPTURE.
+  bool use_testing_device_source_;

[perkj_chrome, 2014/04/15 09:34:01]

We want to get rid of this type of things in the production code. You should be
able to just have it in a test implemenetation of VideoCaptureDeviceFactory.

[mcasas, 2014/04/15 13:47:09]

Done.

 
   // Accessed on the device thread only.
   std::map<media::VideoCaptureSessionId, gfx::NativeViewId>