Add instrumentation to the MessagePumpMac family of classes.

base/message_loop/message_pump_mac.h

Index: base/message_loop/message_pump_mac.h
diff --git a/base/message_loop/message_pump_mac.h b/base/message_loop/message_pump_mac.h
index 748b26591f0403baaaa88fc9ad070135c8565f3b..3fb9db33c3ab6c15dffcb7083652a01367617ef8 100644
--- a/base/message_loop/message_pump_mac.h
+++ b/base/message_loop/message_pump_mac.h
@@ -36,6 +36,8 @@
 
 #include <CoreFoundation/CoreFoundation.h>
 
+#include "base/memory/weak_ptr.h"
+
 #if !defined(__OBJC__)
 class NSAutoreleasePool;
 #else  // !defined(__OBJC__)
@@ -57,6 +59,7 @@ class NSAutoreleasePool;
 
 namespace base {
 
+class MessagePumpInstrumentation;
 class RunLoop;
 class TimeTicks;
 
@@ -93,6 +96,11 @@ class MessagePumpCFRunLoopBase : public MessagePump {
   // objects autoreleased by work to fall into the current autorelease pool.
   virtual NSAutoreleasePool* CreateAutoreleasePool();
 
+  // Enables instrumentation of the MessagePump. See MessagePumpInstrumentation
+  // in the implementation for details.
+  void EnableInstrumentation();
+  WeakPtr<MessagePumpInstrumentation> instrumentation_;
+
  private:
   // Timer callback scheduled by ScheduleDelayedWork.  This does not do any
   // work, but it signals work_source_ so that delayed work can be performed
@@ -106,11 +114,11 @@ class MessagePumpCFRunLoopBase : public MessagePump {
   static void RunWorkSource(void* info);
   bool RunWork();
 
-  // Perform idle-priority work.  This is normally called by PreWaitObserver,
-  // but is also associated with idle_work_source_.  When this function
-  // actually does perform idle work, it will resignal that source.  The
-  // static method calls the instance method; the instance method returns
-  // true if idle work was done.
+  // Perform idle-priority work.  This is normally called by
+  // PrePostWaitObserver, but is also associated with idle_work_source_.  When
+  // this function actually does perform idle work, it will resignal that
+  // source.  The static method calls the instance method; the instance method
+  // returns true if idle work was done.
   static void RunIdleWorkSource(void* info);
   bool RunIdleWork();
 
@@ -132,8 +140,8 @@ class MessagePumpCFRunLoopBase : public MessagePump {
 
   // Observer callback responsible for performing idle-priority work, before
   // the run loop goes to sleep.  Associated with idle_work_observer_.
-  static void PreWaitObserver(CFRunLoopObserverRef observer,
-                              CFRunLoopActivity activity, void* info);
+  static void PrePostWaitObserver(CFRunLoopObserverRef observer,

[jar (doing other things), 2013/08/22 23:03:39]

This name seems worse than the original.  What semantic difference are you
trying to illuminate?

The old name seemed to mean that this observer was called just before waiting
(which seems like the right time to call for idle work, as we're about to
sleep).

The new names seems to mean that just after we're done waiting (yikes: When we
wake up due to scheduled work?) we call this observer before we call the
PostWaitObserver?.  

[Robert Sesek, 2013/08/23 16:58:24]

It matches the EnterExit observer that's already present. The name is trying to
convey that it is called prior to going to sleep and after waking up.

+                                  CFRunLoopActivity activity, void* info);
 
   // Observer callback called before the run loop processes any sources.
   // Associated with pre_source_observer_.