Give performance_browser_tests lots of love and attention.

media/capture/content/thread_safe_capture_oracle.cc

Index: media/capture/content/thread_safe_capture_oracle.cc
diff --git a/media/capture/content/thread_safe_capture_oracle.cc b/media/capture/content/thread_safe_capture_oracle.cc
index 0f817d14ab661385d26a60344030b6126b6ddba2..c7a97814b0c66d838290bcbd5683b0661ba550f4 100644
--- a/media/capture/content/thread_safe_capture_oracle.cc
+++ b/media/capture/content/thread_safe_capture_oracle.cc
@@ -212,20 +212,20 @@ void ThreadSafeCaptureOracle::DidCaptureFrame(
     scoped_refptr<VideoFrame> frame,
     base::TimeTicks reference_time,
     bool success) {
-  TRACE_EVENT_ASYNC_END2("gpu.capture", "Capture", buffer.id, "success",
-                         success, "timestamp",
-                         reference_time.ToInternalValue());
-
   base::AutoLock guard(lock_);
 
-  if (!oracle_.CompleteCapture(frame_number, success, &reference_time))
-    return;
+  const bool should_deliver_frame =
+      oracle_.CompleteCapture(frame_number, success, &reference_time);
 
-  TRACE_EVENT_INSTANT0("gpu.capture", "CaptureSucceeded",
-                       TRACE_EVENT_SCOPE_THREAD);
+  // The following is used by
+  // chrome/browser/extension/api/cast_streaming/performance_test.cc, in
+  // addition to the usual runtime tracing.
+  TRACE_EVENT_ASYNC_END2("gpu.capture", "Capture", buffer.id, "success",
+                         should_deliver_frame, "timestamp",
+                         (reference_time - base::TimeTicks()).InMicroseconds());
 
-  if (!client_)
-    return;  // Capture is stopped.
+  if (!should_deliver_frame || !client_)
+    return;
 
   frame->metadata()->SetDouble(VideoFrameMetadata::FRAME_RATE,
                                params_.requested_format.frame_rate);