Implement mac version of AppRTCDemo.

- Refactored and moved AppRTCDemo to support sharing AppRTC connection code between iOS and mac counterparts.
- Refactored OpenGL rendering code to be shared between iOS and mac counterparts.
- iOS AppRTCDemo now respects video aspect ratio.

BUG=2168
R=fischman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/17589004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6291 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/examples/objc/AppRTCDemo/GAEChannelClient.h b/talk/examples/objc/AppRTCDemo/GAEChannelClient.h
new file mode 100644
index 0000000..2eac214
--- /dev/null
+++ b/talk/examples/objc/AppRTCDemo/GAEChannelClient.h
@@ -0,0 +1,49 @@
+/*
+ * libjingle
+ * Copyright 2013, Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import <Foundation/Foundation.h>
+
+// These methods will be called by the AppEngine chanel.  The documentation
+// for these methods is found here.  (Yes, it is a JS API.)
+// https://developers.google.com/appengine/docs/java/channel/javascript
+@protocol GAEMessageHandler<NSObject>
+
+- (void)onOpen;
+- (void)onMessage:(NSDictionary*)data;
+- (void)onClose;
+- (void)onError:(int)code withDescription:(NSString*)description;
+
+@end
+
+// Initialize with a token for an AppRTC data channel.  This will load
+// ios_channel.html and use the token to establish a data channel between the
+// application and AppEngine.
+@interface GAEChannelClient : NSObject
+
+- (id)initWithToken:(NSString*)token delegate:(id<GAEMessageHandler>)delegate;
+
+@end