Handle early destruction of CanvasCaptureHandler

content/renderer/media/canvas_capture_handler.cc

Index: content/renderer/media/canvas_capture_handler.cc
diff --git a/content/renderer/media/canvas_capture_handler.cc b/content/renderer/media/canvas_capture_handler.cc
index fd6e55f26818448d57e3964dac05b3526b0778f5..818ce40f3b22934ed0b26a0dd7132167c4a33e8d 100644
--- a/content/renderer/media/canvas_capture_handler.cc
+++ b/content/renderer/media/canvas_capture_handler.cc
@@ -58,15 +58,16 @@ class CanvasCaptureHandler::VideoCapturerSource
   }
   void StopCapture() override {
     DCHECK(main_render_thread_checker_.CalledOnValidThread());
-    canvas_handler_->StopVideoCapture();
+    if (canvas_handler_.get())
+      canvas_handler_->StopVideoCapture();
   }
 
  private:
   double frame_rate_;

[mcasas, 2016/03/23 17:54:30]

const? :)

[emircan, 2016/03/23 22:12:03]

Done :)

   // Bound to Main Render thread.
   base::ThreadChecker main_render_thread_checker_;
-  // CanvasCaptureHandler is owned by CanvasDrawListener in blink and
-  // guaranteed to be alive during the lifetime of this class.
+  // CanvasCaptureHandler is owned by CanvasDrawListener in blink and might be
+  // destructed before StopCapture() call.

[mcasas, 2016/03/23 17:54:30]

nit: s/destructed/destroyed/ ?

[emircan, 2016/03/23 22:12:03]

Done.

   base::WeakPtr<CanvasCaptureHandler> canvas_handler_;
 };