Renamed VideoSourceInterface to VideoTrackSourceInterface.

Moved VideoSourceInterface to MediaStreamInterface.h
Renamed VideoSourceTest to VideoCapturerTrackSourceTest
Renamed VideoSource to VideoCaptureTrackSource and cl lint and cl format.
BUG=webrtc:5426
TBR=pthatcher@webrtc.org

Review URL: https://codereview.webrtc.org/1770003002 .

Cr-Commit-Position: refs/heads/master@{#11893}
diff --git a/webrtc/api/peerconnectionfactory.h b/webrtc/api/peerconnectionfactory.h
index 1bc40ed..b47f75a 100644
--- a/webrtc/api/peerconnectionfactory.h
+++ b/webrtc/api/peerconnectionfactory.h
@@ -63,19 +63,19 @@
   rtc::scoped_refptr<AudioSourceInterface> CreateAudioSource(
       const MediaConstraintsInterface* constraints) override;
 
-  virtual rtc::scoped_refptr<VideoSourceInterface> CreateVideoSource(
+  virtual rtc::scoped_refptr<VideoTrackSourceInterface> CreateVideoSource(
       cricket::VideoCapturer* capturer) override;
   // This version supports filtering on width, height and frame rate.
   // For the "constraints=null" case, use the version without constraints.
   // TODO(hta): Design a version without MediaConstraintsInterface.
   // https://bugs.chromium.org/p/webrtc/issues/detail?id=5617
-  rtc::scoped_refptr<VideoSourceInterface> CreateVideoSource(
+  rtc::scoped_refptr<VideoTrackSourceInterface> CreateVideoSource(
       cricket::VideoCapturer* capturer,
       const MediaConstraintsInterface* constraints) override;
 
-  rtc::scoped_refptr<VideoTrackInterface>
-      CreateVideoTrack(const std::string& id,
-                       VideoSourceInterface* video_source) override;
+  rtc::scoped_refptr<VideoTrackInterface> CreateVideoTrack(
+      const std::string& id,
+      VideoTrackSourceInterface* video_source) override;
 
   rtc::scoped_refptr<AudioTrackInterface>
       CreateAudioTrack(const std::string& id,