Update from https://crrev.com/302630

base/profiler/scoped_tracker.h

Index: base/profiler/scoped_tracker.h
diff --git a/base/profiler/scoped_tracker.h b/base/profiler/scoped_tracker.h
index fbd73099bcf122f59b2d639b381939c177120a0c..a1885571351a7a7ca31a3d63e80342743b0d220f 100644
--- a/base/profiler/scoped_tracker.h
+++ b/base/profiler/scoped_tracker.h
@@ -10,6 +10,7 @@
 // found using profiler data.
 
 #include "base/base_export.h"
+#include "base/callback_forward.h"
 #include "base/location.h"
 #include "base/profiler/scoped_profile.h"
 
@@ -26,6 +27,14 @@ class BASE_EXPORT ScopedTracker {
   // this function is not called, all profiler instrumentations are no-ops.
   static void Enable();
 
+  // Augments a |callback| with provided |location|. This is useful for
+  // instrumenting cases when we know that a jank is in a callback and there are
+  // many possible callbacks, but they come from a relatively small number of
+  // places. We can instrument these few places and at least know which one
+  // passes the janky callback.
+  static base::Closure TrackCallback(const Location& location,
+                                     const base::Closure& callback);
+
  private:
   const ScopedProfile scoped_profile_;