Report expected task queueing time via UMA

components/scheduler/base/task_time_tracker.h

Index: components/scheduler/base/task_time_tracker.h
diff --git a/components/scheduler/base/task_time_tracker.h b/components/scheduler/base/task_time_tracker.h
new file mode 100644
index 0000000000000000000000000000000000000000..8546229f6fcc928553a6b98b469b48214df7550c
--- /dev/null
+++ b/components/scheduler/base/task_time_tracker.h
@@ -0,0 +1,26 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_RENDERER_SCHEDULER_BASE_TASK_TIME_TRACKER_H_
+#define CONTENT_RENDERER_SCHEDULER_BASE_TASK_TIME_TRACKER_H_
+
+#include "base/time/time.h"
+#include "components/scheduler/scheduler_export.h"
+
+namespace scheduler {
+
+class SCHEDULER_EXPORT TaskTimeTracker {
+ public:
+  TaskTimeTracker() {}
+  virtual ~TaskTimeTracker() {}
+
+  virtual void ReportTaskTime(base::TimeTicks startTime,
+                              base::TimeTicks endTime) = 0;
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TaskTimeTracker);
+};
+
+} // namespace scheduler
+
+#endif // CONTENT_RENDERER_SCHEDULER_BASE_TASK_TIME_TRACKER_H_