Modifies SDK and iOS detection for helper method that needs iOS 9+

webrtc/modules/utility/include/helpers_ios.h

 /*
  *  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.
  */
 
@@ skipping 19 matching lines @@
 
 // Returns [NSThread currentThread] description as string.
 // Example: <NSThread: 0x170066d80>{number = 1, name = main}
 std::string GetCurrentThreadDescription();
 
 std::string GetAudioSessionCategory();
 
 // Returns the current name of the operating system.
 std::string GetSystemName();
 
-// Returns the current version of the operating system.
-std::string GetSystemVersion();
+// Returns the current version of the operating system as a string.
+std::string GetSystemVersionAsString();
 
-// Returns the version of the operating system as a floating point value.
-float GetSystemVersionAsFloat();
+// Returns the version of the operating system in double representation.
+// Uses a cached value of the system version.
+double GetSystemVersion();
 
 // Returns the device type.
 // Examples: ”iPhone” and ”iPod touch”.
 std::string GetDeviceType();
 
 // Returns a more detailed device name.
 // Examples: "iPhone 5s (GSM)" and "iPhone 6 Plus".
 std::string GetDeviceName();
 
 // Returns the name of the process. Does not uniquely identify the process.
@@ skipping 12 matching lines @@
 
 // Indicates whether Low Power Mode is enabled on the iOS device.
 bool GetLowPowerModeEnabled();
 
 }  // namespace ios
 }  // namespace webrtc
 
 #endif  // defined(WEBRTC_IOS)
 
 #endif  // WEBRTC_MODULES_UTILITY_INCLUDE_HELPERS_IOS_H_