Added AVFoundation Glue and Device Monitoring for Mac.

media/video/capture/mac/avfoundation_glue.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MEDIA_VIDEO_CAPTURE_MAC_AVFOUNDATION_GLUE_H_
+#define MEDIA_VIDEO_CAPTURE_MAC_AVFOUNDATION_GLUE_H_
+

[Mark Mentovai, 2013/09/26 17:09:10]

You need a comment saying why we have to do this instead of linking against the
AVFoundation framework directly.

[mcasas, 2013/09/30 17:53:50]

Done.

+#import <Foundation/Foundation.h>
+
+@interface AVFoundationGlue : NSObject
+
+// This method returns YES if the OS version supports AVFoundation and the
+// AVFoundation Bundle could be loaded correctly, or NO otherwise.

[Mark Mentovai, 2013/09/26 17:09:10]

bundle uses a lowercase b.

[mcasas, 2013/09/30 17:53:50]

Done.

++ (BOOL)IsAVFoundationSupported;

[Mark Mentovai, 2013/09/26 17:09:10]

See previous comment about naming.

[mcasas, 2013/09/30 17:53:50]

Done. Again, IsOsLionOrLater().

+
++ (NSBundle*)getAVFoundationBundle;

[Mark Mentovai, 2013/09/26 17:09:10]

Normal naming would just be avFoundationBundle.

[mcasas, 2013/09/30 17:53:50]

Done.

+
+@end  // @interface AVFoundationGlue
+
+// Coming from AVCaptureDevice.h
+@interface AVCaptureDeviceGlue : NSObject
+
++ (NSArray *)devices;

[Mark Mentovai, 2013/09/26 17:09:10]

Above, you nestled the * up against the type name. Here, you put a space in
between. Be consistent. Chromium code tends to prefer it without the space.

[mcasas, 2013/09/30 17:53:50]

Done.

+
+- (BOOL)hasMediaType:(NSString *)mediaType;
+
+@end
+
+extern NSString* const AVCaptureDeviceWasConnectedNotification =
+    @"AVCaptureDeviceWasConnectedNotification";

[Mark Mentovai, 2013/09/26 17:09:10]

You shouldn’t hard-code these 5 strings, you should pull them out of the bundle
dynamically.

[mcasas, 2013/09/30 17:53:50]

I couldn't do this because the strings are defined at the root level of the
AVFoundation, not inside a class, and couldn't find a way to get them from the
NSBundle... :(

+extern NSString* const AVCaptureDeviceWasDisconnectedNotification =
+    @"AVCaptureDeviceWasDisconnectedNotification";
+
+// Coming from AVMediaFormat.h
+extern NSString* const AVMediaTypeVideo = @"vide";
+extern NSString* const AVMediaTypeAudio = @"soun";
+extern NSString* const AVMediaTypeMuxed = @"muxx";
+
+#endif  // MEDIA_VIDEO_CAPTURE_MAC_AVFOUNDATION_GLUE_H_