Cleanup Semaphore class.

src/debug.h

Index: src/debug.h
diff --git a/src/debug.h b/src/debug.h
index 2333b07febfea1fcc88a5916ef47af009227fdc4..042b9bb99b5c2714b789ace4ca713c6b8c9d3881 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -820,7 +820,7 @@ class Debugger {
   void SetEventListener(Handle<Object> callback, Handle<Object> data);
   void SetMessageHandler(v8::Debug::MessageHandler2 handler);
   void SetHostDispatchHandler(v8::Debug::HostDispatchHandler handler,
-                              int period);
+                              TimeDelta period);
   void SetDebugMessageDispatchHandler(
       v8::Debug::DebugMessageDispatchHandler handler,
       bool provide_locker);
@@ -931,13 +931,13 @@ class Debugger {
   Mutex dispatch_handler_access_;  // Mutex guarding dispatch handler.
   v8::Debug::DebugMessageDispatchHandler debug_message_dispatch_handler_;
   MessageDispatchHelperThread* message_dispatch_helper_thread_;
-  int host_dispatch_micros_;
+  TimeDelta host_dispatch_period_;
 
   DebuggerAgent* agent_;
 
   static const int kQueueInitialSize = 4;
   LockingCommandMessageQueue command_queue_;
-  Semaphore* command_received_;  // Signaled for each command received.
+  Semaphore command_received_;  // Signaled for each command received.
   LockingCommandMessageQueue event_command_queue_;
 
   Isolate* isolate_;
@@ -1046,7 +1046,7 @@ class Debug_Address {
 class MessageDispatchHelperThread: public Thread {
  public:
   explicit MessageDispatchHelperThread(Isolate* isolate);
-  ~MessageDispatchHelperThread();
+  ~MessageDispatchHelperThread() {}
 
   void Schedule();
 
@@ -1054,7 +1054,7 @@ class MessageDispatchHelperThread: public Thread {
   void Run();
 
   Isolate* isolate_;
-  Semaphore* const sem_;
+  Semaphore sem_;
   Mutex mutex_;
   bool already_signalled_;