De-dupe copy requests for tab capture in DelegatedFrameHost.

content/browser/media/capture/video_capture_oracle.h

Index: content/browser/media/capture/video_capture_oracle.h
diff --git a/content/browser/media/capture/video_capture_oracle.h b/content/browser/media/capture/video_capture_oracle.h
index 8728ace6ef91b651c60afacf06896692c0495bc6..cac7d1947578d13508e92ecb19025e5e3b4bfc9f 100644
--- a/content/browser/media/capture/video_capture_oracle.h
+++ b/content/browser/media/capture/video_capture_oracle.h
@@ -199,6 +199,9 @@ class CONTENT_EXPORT VideoCaptureOracle {
   // be provided to the consumer of the frame.
   bool CompleteCapture(int frame_number, base::TimeTicks* frame_timestamp);
 
+  // Notify on the abort/failure of a capture.
+  void CaptureAbortedOrFailed(int frame_number);
+
   base::TimeDelta min_capture_period() const {
     return smoothing_sampler_.min_capture_period();
   }
@@ -218,6 +221,10 @@ class CONTENT_EXPORT VideoCaptureOracle {
   // Stores the frame number from the last delivered frame.
   int last_delivered_frame_number_;
 
+  // The most-recent consecutive range of aborted captures.
+  int first_failed_frame_number_;
+  int last_failed_frame_number_;
+
   // These track present/paint history and propose whether to sample each event
   // for capture.  |smoothing_sampler_| uses a "works for all" heuristic, while
   // |content_sampler_| specifically detects animated content (e.g., video