[ios] fix code standard; update for 64bit

ios/media/video_and_photos/play_a_video_using_avplayer/AVPlayerDemo/AVPlayerDemo.csproj

@@ -28,7 +28,7 @@
     <MtouchUseRefCounting>true</MtouchUseRefCounting>
     <MtouchI18n>
     </MtouchI18n>
-    <MtouchArch>i386</MtouchArch>
+    <MtouchArch>i386, x86_64</MtouchArch>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhoneSimulator' ">
     <DebugType>none</DebugType>
@@ -51,7 +51,7 @@
     <CodesignKey>iPhone Developer</CodesignKey>
     <MtouchDebug>true</MtouchDebug>
     <MtouchProfiling>true</MtouchProfiling>
-    <MtouchArch>ARMv7</MtouchArch>
+    <MtouchArch>ARMv7, ARMv7s, ARM64</MtouchArch>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhone' ">
     <DebugType>none</DebugType>

ios/media/video_and_photos/play_a_video_using_avplayer/AVPlayerDemo/AVPlayerDemoViewController.cs

@@ -8,10 +8,10 @@ namespace AVPlayerDemo
 {
     public partial class AVPlayerDemoViewController : UIViewController
     {
-        AVPlayer _player;
-        AVPlayerLayer _playerLayer;
-        AVAsset _asset;
-        AVPlayerItem _playerItem;
+		AVPlayer player;
+		AVPlayerLayer playerLayer;
+        AVAsset asset;
+		AVPlayerItem playerItem;
         
         public AVPlayerDemoViewController () : base ("AVPlayerDemoViewController", null)
         {
@@ -29,16 +29,16 @@ namespace AVPlayerDemo
         {
             base.ViewDidLoad ();
             
-            _asset = AVAsset.FromUrl (NSUrl.FromFilename ("sample.m4v"));
-            _playerItem = new AVPlayerItem (_asset);   
+            asset = AVAsset.FromUrl (NSUrl.FromFilename ("sample.m4v"));
+            playerItem = new AVPlayerItem (asset);   
             
-            _player = new AVPlayer (_playerItem);  
-            _playerLayer = AVPlayerLayer.FromPlayer (_player);
-            _playerLayer.Frame = View.Frame;
+            player = new AVPlayer (playerItem);  
+            playerLayer = AVPlayerLayer.FromPlayer (player);
+            playerLayer.Frame = View.Frame;
             
-            View.Layer.AddSublayer (_playerLayer);
+            View.Layer.AddSublayer (playerLayer);
             
-            _player.Play ();
+            player.Play ();
         }
         
         public override void ViewDidUnload ()