Move ios_helpers to sdk folder

webrtc/sdk/objc/Framework/Classes/helpers.mm

 /*
  *  Copyright (c) 2015 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.
  */
 
 #if defined(WEBRTC_IOS)
 
 #import <AVFoundation/AVFoundation.h>
 #import <Foundation/Foundation.h>
 #import <sys/sysctl.h>
 #import <UIKit/UIKit.h>
 
 #include <memory>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
-#include "webrtc/modules/audio_device/ios/helpers_ios.h"
+#include "webrtc/sdk/objc/Framework/Classes/helpers.h"
 
 namespace webrtc {
 namespace ios {
 
 bool isOperatingSystemAtLeastVersion(double version) {
   return GetSystemVersion() >= version;
 }
 
 // Internal helper method used by GetDeviceName() to return device name.
 const char* LookUpRealName(const char* raw_name) {
@@ skipping 46 matching lines @@
   };
 
   for (auto& d : device_names) {
     if (strcmp(d.raw_name, raw_name) == 0)
       return d.real_name;
   }
   LOG(LS_WARNING) << "Failed to find device name (" << raw_name << ")";
   return "";
 }
 
-// TODO(henrika): move to shared location.
-// See https://code.google.com/p/webrtc/issues/detail?id=4773 for details.
 NSString* NSStringFromStdString(const std::string& stdString) {
   // std::string may contain null termination character so we construct
   // using length.
   return [[NSString alloc] initWithBytes:stdString.data()
                                   length:stdString.length()
                                 encoding:NSUTF8StringEncoding];
 }
 
 std::string StdStringFromNSString(NSString* nsString) {
   NSData* charData = [nsString dataUsingEncoding:NSUTF8StringEncoding];
@@ skipping 87 matching lines @@
   LOG(LS_WARNING) << "webrtc::ios::GetLowPowerModeEnabled() is not "
                      "supported. Requires at least iOS 9.0";
   return false;
 }
 #endif
 
 }  // namespace ios
 }  // namespace webrtc
 
 #endif  // defined(WEBRTC_IOS)