Fix WebRTC API framework build.

BUG=webrtc:5737

Review URL: https://codereview.webrtc.org/1875003004

Cr-Commit-Position: refs/heads/master@{#12391}
diff --git a/webrtc/api/objc/RTCAVFoundationVideoSource.h b/webrtc/api/objc/RTCAVFoundationVideoSource.h
index 6d224d3..8c0232a 100644
--- a/webrtc/api/objc/RTCAVFoundationVideoSource.h
+++ b/webrtc/api/objc/RTCAVFoundationVideoSource.h
@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#import "RTCVideoSource.h"
+#import "webrtc/api/objc/RTCVideoSource.h"
 
 @class AVCaptureSession;
 @class RTCMediaConstraints;