WeakPtr destruction order cleanup: media edition.

media/video/capture/mac/video_capture_device_mac.h

 // Copyright (c) 2012 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.
 
 // MacOSX implementation of generic VideoCaptureDevice, using either QTKit or
 // AVFoundation as native capture API. QTKit is used in OSX versions 10.6 and
 // previous, and AVFoundation is used in the rest.
 
 #ifndef MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_MAC_H_
 #define MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_MAC_H_
@@ skipping 54 matching lines @@
   scoped_ptr<VideoCaptureDevice::Client> client_;
 
   VideoCaptureFormat capture_format_;
   bool sent_frame_info_;
   bool tried_to_square_pixels_;
 
   // Only read and write state_ from inside this loop.
   const scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   InternalState state_;
 
-  // Used with Bind and PostTask to ensure that methods aren't called
-  // after the VideoCaptureDeviceMac is destroyed.
+  id<PlatformVideoCapturingMac> capture_device_;
+
+  // Used with Bind and PostTask to ensure that methods aren't called after the
+  // VideoCaptureDeviceMac is destroyed.  NOTE: This must always be last so it's
+  // invalidated before other member variables might be accessed.
   base::WeakPtrFactory<VideoCaptureDeviceMac> weak_factory_;
-  base::WeakPtr<VideoCaptureDeviceMac> weak_this_;
-
-  id<PlatformVideoCapturingMac> capture_device_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureDeviceMac);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_MAC_H_