We have a problem in the process on destroying WebContentsImpl because

content/browser/media/capture/web_contents_video_capture_device.cc

Index: content/browser/media/capture/web_contents_video_capture_device.cc
diff --git a/content/browser/media/capture/web_contents_video_capture_device.cc b/content/browser/media/capture/web_contents_video_capture_device.cc
index 1ce22a224f26e5446c71a79f1a29ceb5630e8154..036dc87d703130c1077715ae6cef13edaa40bfb9 100644
--- a/content/browser/media/capture/web_contents_video_capture_device.cc
+++ b/content/browser/media/capture/web_contents_video_capture_device.cc
@@ -278,7 +278,7 @@ class WebContentsCaptureMachine
     RenewFrameSubscription();
   }
 
-  virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE;
+  virtual void WebContentsDestroyed() OVERRIDE;
 
  private:
   // Starts observing the web contents, returning false if lookup fails.
@@ -705,12 +705,11 @@ bool WebContentsCaptureMachine::StartObservingWebContents() {
   return false;
 }
 
-void WebContentsCaptureMachine::WebContentsDestroyed(
-    WebContents* web_contents) {
+void WebContentsCaptureMachine::WebContentsDestroyed() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   subscription_.reset();
-  web_contents->DecrementCapturerCount();
+  web_contents()->DecrementCapturerCount();
   oracle_proxy_->ReportError("WebContentsDestroyed()");
 }