Add unit tests for avfoundation format mapper functions and fix wrong implementation.

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

Index: webrtc/sdk/objc/Framework/Classes/avfoundationformatmapper.h
diff --git a/webrtc/sdk/objc/Framework/Classes/avfoundationformatmapper.h b/webrtc/sdk/objc/Framework/Classes/avfoundationformatmapper.h
index 9af55e9b0efef21d5c53bf46cd508b83838abe95..0f357a06608beb52b5778bd8142e7938fee12553 100644
--- a/webrtc/sdk/objc/Framework/Classes/avfoundationformatmapper.h
+++ b/webrtc/sdk/objc/Framework/Classes/avfoundationformatmapper.h
@@ -8,6 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <set>
+
 #import <AVFoundation/AVFoundation.h>
 #import <Foundation/Foundation.h>
 
@@ -16,12 +18,12 @@
 namespace webrtc {
 // Mapping from AVCaptureDeviceFormat to cricket::VideoFormat for given input
 // device.
-extern std::set<cricket::VideoFormat> GetSupportedVideoFormatsForDevice(
+std::set<cricket::VideoFormat> GetSupportedVideoFormatsForDevice(
     AVCaptureDevice* device);
 
 // Sets device format for the provided capture device. Returns YES/NO depending
 // on success.
-extern bool SetFormatForCaptureDevice(AVCaptureDevice* device,
-                                      AVCaptureSession* session,
-                                      const cricket::VideoFormat& format);
+bool SetFormatForCaptureDevice(AVCaptureDevice* device,
+                               AVCaptureSession* session,
+                               const cricket::VideoFormat& format);
 }