Reland of name AppRTCDemo on Android and iOS to AppRTCMobile (patchset #1 id:1 of https://codereview.webrtc.org/2358133003/ )

Reason for revert:
Internal project is updated.

Original issue's description:
> Revert of Rename AppRTCDemo on Android and iOS to AppRTCMobile (patchset #2 id:20001 of https://codereview.webrtc.org/2343403002/ )
>
> Reason for revert:
> Breaks internal project.
>
> Original issue's description:
> > Rename AppRTCDemo on Android and iOS to AppRTCMobile
> >
> > The purpose is to make it clearer it is a mobile application.
> >
> > BUG=webrtc:6359
> > NOPRESUBMIT=true
> >
> > Committed: https://crrev.com/d3af58bdab5b25acd62cd816363becc7003d3e5a
> > Cr-Commit-Position: refs/heads/master@{#14356}
>
> TBR=sakal@webrtc.org,kthelgason@webrtc.org,tommi@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6359
>
> Committed: https://crrev.com/87ef6f750126f9f17f4714d696a8e77a2dd0a3f1
> Cr-Commit-Position: refs/heads/master@{#14358}

TBR=sakal@webrtc.org,kthelgason@webrtc.org,tommi@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6359

Review URL: https://codereview.webrtc.org/2373443005 .

Cr-Commit-Position: refs/heads/master@{#14391}

webrtc/examples/objc/AppRTCMobile/mac/APPRTCViewController.h

@@ -0,0 +1,17 @@
+/*
+ *  Copyright 2014 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 <AppKit/AppKit.h>
+
+@interface APPRTCViewController : NSViewController
+
+- (void)windowWillClose:(NSNotification*)notification;
+
+@end