Move and rename TaskTimeTracker to public interface exposed to WebThread, use in WebPerf Agent.

third_party/WebKit/Source/platform/scheduler/child/webthread_base.cc

Index: third_party/WebKit/Source/platform/scheduler/child/webthread_base.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/child/webthread_base.cc b/third_party/WebKit/Source/platform/scheduler/child/webthread_base.cc
index c27706f13978a9a3cf90ebb6c4b96e6e6b046a9f..b6b2f59ca8f916747db90b34516aaea4d8b75485 100644
--- a/third_party/WebKit/Source/platform/scheduler/child/webthread_base.cc
+++ b/third_party/WebKit/Source/platform/scheduler/child/webthread_base.cc
@@ -63,6 +63,14 @@ void WebThreadBase::removeTaskObserver(TaskObserver* observer) {
   task_observer_map_.erase(iter);
 }
 
+void WebThreadBase::addTaskTimeObserver(TaskTimeObserver* task_time_observer) {
+    AddTaskTimeObserverInternal(task_time_observer);

[alph, 2016/08/22 22:21:27]

nit: something wrong with indentation here.

[panicker, 2016/08/22 23:14:15]

Acknowledged.

+}
+
+void WebThreadBase::removeTaskTimeObserver(TaskTimeObserver* task_time_observer) {
+    RemoveTaskTimeObserverInternal(task_time_observer);
+}
+
 void WebThreadBase::AddTaskObserverInternal(
     base::MessageLoop::TaskObserver* observer) {
   base::MessageLoop::current()->AddTaskObserver(observer);