"Buttery Smooth" Tab Capture.

content/browser/media/capture/content_video_capture_device_core.cc

Index: content/browser/media/capture/content_video_capture_device_core.cc
diff --git a/content/browser/media/capture/content_video_capture_device_core.cc b/content/browser/media/capture/content_video_capture_device_core.cc
index 6878652de0736683eeca1bfa3f6b6a58763ae3e8..8152b3dbe0e9cc19636190fff20137c9555ec88f 100644
--- a/content/browser/media/capture/content_video_capture_device_core.cc
+++ b/content/browser/media/capture/content_video_capture_device_core.cc
@@ -66,6 +66,7 @@ ThreadSafeCaptureOracle::~ThreadSafeCaptureOracle() {}
 
 bool ThreadSafeCaptureOracle::ObserveEventAndDecideCapture(
     VideoCaptureOracle::Event event,
+    const gfx::Rect& damage_rect,
     base::TimeTicks event_time,
     scoped_refptr<media::VideoFrame>* storage,
     CaptureFrameCallback* callback) {
@@ -78,7 +79,7 @@ bool ThreadSafeCaptureOracle::ObserveEventAndDecideCapture(
       client_->ReserveOutputBuffer(video_frame_format_,
                                    params_.requested_format.frame_size);
   const bool should_capture =
-      oracle_->ObserveEventAndDecideCapture(event, event_time);
+      oracle_->ObserveEventAndDecideCapture(event, damage_rect, event_time);
   const bool content_is_dirty =
       (event == VideoCaptureOracle::kCompositorUpdate ||
        event == VideoCaptureOracle::kSoftwarePaint);
@@ -90,7 +91,7 @@ bool ThreadSafeCaptureOracle::ObserveEventAndDecideCapture(
   // Consider the various reasons not to initiate a capture.
   if (should_capture && !output_buffer) {
     TRACE_EVENT_INSTANT1("mirroring",
-                         "EncodeLimited",
+                         "PipelineLimited",
                          TRACE_EVENT_SCOPE_THREAD,
                          "trigger",
                          event_name);
@@ -108,7 +109,7 @@ bool ThreadSafeCaptureOracle::ObserveEventAndDecideCapture(
   } else if (!should_capture && !output_buffer) {
     // We decided not to capture, but we wouldn't have been able to if we wanted
     // to because no output buffer was available.
-    TRACE_EVENT_INSTANT1("mirroring", "NearlyEncodeLimited",
+    TRACE_EVENT_INSTANT1("mirroring", "NearlyPipelineLimited",
                          TRACE_EVENT_SCOPE_THREAD,
                          "trigger", event_name);
     return false;
@@ -192,7 +193,7 @@ void ThreadSafeCaptureOracle::DidCaptureFrame(
     return;  // Capture is stopped.
 
   if (success) {
-    if (oracle_->CompleteCapture(frame_number, timestamp)) {
+    if (oracle_->CompleteCapture(frame_number, &timestamp)) {
       media::VideoCaptureFormat format = params_.requested_format;
       format.frame_size = frame->coded_size();
       client_->OnIncomingCapturedVideoFrame(buffer, format, frame, timestamp);