Compile ios helpers on mac as well.

webrtc/sdk/BUILD.gn

 # Copyright 2016 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("../webrtc.gni")
 if (is_ios) {
@@ skipping 29 matching lines @@
       "objc/Framework/Classes/NSString+StdString.h",
       "objc/Framework/Classes/NSString+StdString.mm",
       "objc/Framework/Classes/RTCDispatcher.m",
       "objc/Framework/Classes/RTCFieldTrials.mm",
       "objc/Framework/Classes/RTCLogging.mm",
       "objc/Framework/Classes/RTCMetrics.mm",
       "objc/Framework/Classes/RTCMetricsSampleInfo+Private.h",
       "objc/Framework/Classes/RTCMetricsSampleInfo.mm",
       "objc/Framework/Classes/RTCSSLAdapter.mm",
       "objc/Framework/Classes/RTCTracing.mm",
+      "objc/Framework/Classes/helpers.h",
+      "objc/Framework/Classes/helpers.mm",
       "objc/Framework/Headers/WebRTC/RTCDispatcher.h",
       "objc/Framework/Headers/WebRTC/RTCFieldTrials.h",
       "objc/Framework/Headers/WebRTC/RTCLogging.h",
       "objc/Framework/Headers/WebRTC/RTCMacros.h",
       "objc/Framework/Headers/WebRTC/RTCMetrics.h",
       "objc/Framework/Headers/WebRTC/RTCMetricsSampleInfo.h",
       "objc/Framework/Headers/WebRTC/RTCSSLAdapter.h",
       "objc/Framework/Headers/WebRTC/RTCTracing.h",
     ]
     if (is_ios) {
       sources += [
         "objc/Framework/Classes/RTCCameraPreviewView.m",
         "objc/Framework/Classes/RTCUIApplication.h",
         "objc/Framework/Classes/RTCUIApplication.mm",
         "objc/Framework/Classes/UIDevice+RTCDevice.mm",
-        "objc/Framework/Classes/helpers.h",
-        "objc/Framework/Classes/helpers.mm",
         "objc/Framework/Headers/WebRTC/RTCCameraPreviewView.h",
         "objc/Framework/Headers/WebRTC/UIDevice+RTCDevice.h",
       ]
       libs = [ "AVFoundation.framework" ]
     }
     if (!build_with_chromium) {
       sources += [
         "objc/Framework/Classes/RTCFileLogger.mm",
         "objc/Framework/Headers/WebRTC/RTCFileLogger.h",
       ]
@@ skipping 319 matching lines @@
       deps += [ "$rtc_libyuv_dir" ]
       public_deps = [
         "$rtc_libyuv_dir",
       ]
     } else {
       # Need to add a directory normally exported by libyuv.
       include_dirs = [ "$rtc_libyuv_dir/include" ]
     }
   }
 }