Adding instrumentation to locate the source of jankiness.

content/browser/loader/power_save_block_resource_throttle.cc

Index: content/browser/loader/power_save_block_resource_throttle.cc
diff --git a/content/browser/loader/power_save_block_resource_throttle.cc b/content/browser/loader/power_save_block_resource_throttle.cc
index 7a084b0a71de0e160c60c0dfe178a6a7ad038313..f0ed06664748d81dc8289c0c1f03f40d8e7816f1 100644
--- a/content/browser/loader/power_save_block_resource_throttle.cc
+++ b/content/browser/loader/power_save_block_resource_throttle.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/profiler/scoped_tracker.h"

[mmenke, 2014/11/17 15:38:16]

This should go above the "content/public/browser/power_save_blocker.h" line

[vadimt, 2014/11/18 01:14:27]

Done.

 #include "content/browser/loader/power_save_block_resource_throttle.h"
 
 #include "content/public/browser/power_save_blocker.h"
@@ -29,6 +30,11 @@ void PowerSaveBlockResourceThrottle::WillStartRequest(bool* defer) {
 }
 
 void PowerSaveBlockResourceThrottle::WillProcessResponse(bool* defer) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422516 PowerSaveBlockResourceThrottle::WillProcessResponse"));
+
   // Stop blocking power save after request finishes.
   power_save_blocker_.reset();
   timer_.Stop();