Add RTCFileVideoCapturer class.

webrtc/sdk/objc/Framework/Classes/RTCFileVideoCapturer.h

Index: webrtc/sdk/objc/Framework/Classes/RTCFileVideoCapturer.h
diff --git a/webrtc/sdk/objc/Framework/Classes/RTCFileVideoCapturer.h b/webrtc/sdk/objc/Framework/Classes/RTCFileVideoCapturer.h
new file mode 100644
index 0000000000000000000000000000000000000000..d94b5269a1eb56b45519a3fab6ec26b7c311f3c7
--- /dev/null
+++ b/webrtc/sdk/objc/Framework/Classes/RTCFileVideoCapturer.h
@@ -0,0 +1,19 @@
+/*
+ *  Copyright 2017 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import <Foundation/Foundation.h>
+#import <WebRTC/RTCVideoCapturer.h>
+
+@interface RTCFileVideoCapturer : RTCVideoCapturer
+
+- (void)startCapturingFromFileNamed:(NSString *)nameOfFile;
+- (void)stopCapture;
+
+@end