Fix for Crash in VideoCaptureController::DoNewBufferOnIOThread

content/browser/renderer_host/media/video_capture_controller.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.
 //
 // VideoCaptureController is the glue between a VideoCaptureDevice and all
 // VideoCaptureHosts that have connected to it. A controller exists on behalf of
 // one (and only one) VideoCaptureDevice; both are owned by the
 // VideoCaptureManager.
 //
 // The VideoCaptureController is responsible for:
@@ skipping 49 matching lines @@
 
 namespace content {
 
 class CONTENT_EXPORT VideoCaptureController : public media::VideoFrameReceiver {
  public:
   VideoCaptureController();
   ~VideoCaptureController() override;
 
   base::WeakPtr<VideoCaptureController> GetWeakPtrForIOThread();
 
-  // Factory code creating instances of VideoCaptureController must set a
-  // FrameBufferPool before any of the media::VideoFrameReceiver are used.
-  // Setting the observer is done in this method separate from the constructor
-  // in order to allow use the media::VideoFrameReceiver methods
-  // before the observer can be provided. (This is the case with
-  // VideoCaptureManager).
+  // A FrameBufferPool must to be set in order for video frames to be
+  // processed. While no FrameBufferPool is set, incoming video frames are
+  // ignored. It is legal to reset a previously set FrameBufferPool by calling
+  // this method with a nullptr.
   void SetFrameBufferPool(
       std::unique_ptr<media::FrameBufferPool> frame_buffer_pool);
 
   // Factory code creating instances of VideoCaptureController may optionally
   // set a VideoFrameConsumerFeedbackObserver. Setting the observer is done in
   // this method separate from the constructor to allow clients to create and
   // use instances before they can provide the observer. (This is the case with
   // VideoCaptureManager).
   void SetConsumerFeedbackObserver(
       std::unique_ptr<media::VideoFrameConsumerFeedbackObserver> observer);
@@ skipping 120 matching lines @@
   media::VideoCaptureFormat video_capture_format_;
 
   base::WeakPtrFactory<VideoCaptureController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_CONTROLLER_H_