Jankometer: Generalize the code more. Add better support for monitoring IO thread.

base/message_loop.cc

Index: base/message_loop.cc
diff --git a/base/message_loop.cc b/base/message_loop.cc
index 7a09f38dd962ef19f31347bba8e0c0870af102c3..3b136170911b10952ec8bdc95325cf70b60f24c5 100644
--- a/base/message_loop.cc
+++ b/base/message_loop.cc
@@ -149,6 +149,16 @@ void MessageLoop::RemoveDestructionObserver(DestructionObserver *obs) {
   destruction_observers_.RemoveObserver(obs);
 }
 
+void MessageLoop::AddTaskObserver(TaskObserver *obs) {
+  DCHECK_EQ(this, current());
+  task_observers_.AddObserver(obs);
+}
+
+void MessageLoop::RemoveTaskObserver(TaskObserver *obs) {
+  DCHECK_EQ(this, current());
+  task_observers_.RemoveObserver(obs);
+}
+
 void MessageLoop::Run() {
   AutoRunState save_state(this);
   RunHandler();
@@ -325,7 +335,10 @@ void MessageLoop::RunTask(Task* task) {
   nestable_tasks_allowed_ = false;
 
   HistogramEvent(kTaskRunEvent);
+  FOR_EACH_OBSERVER(TaskObserver, task_observers_,
+                    WillProcessTask(task->tracked_birth_time()));
   task->Run();
+  FOR_EACH_OBSERVER(TaskObserver, task_observers_, DidProcessTask());
   delete task;
 
   nestable_tasks_allowed_ = true;
@@ -584,16 +597,9 @@ const LinearHistogram::DescriptionPair MessageLoop::event_descriptions_[] = {
 // MessageLoopForUI
 
 #if defined(OS_WIN)
-void MessageLoopForUI::WillProcessMessage(const MSG& message) {
-  pump_win()->WillProcessMessage(message);
-}
 void MessageLoopForUI::DidProcessMessage(const MSG& message) {
   pump_win()->DidProcessMessage(message);
 }
-void MessageLoopForUI::PumpOutPendingPaintMessages() {
-  pump_ui()->PumpOutPendingPaintMessages();
-}
-
 #endif  // defined(OS_WIN)
 
 #if !defined(OS_MACOSX)