Fix isolate getter in DebugAgent

src/debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3743 matching lines @@
 
 
 void LockingCommandMessageQueue::Clear() {
   ScopedLock sl(lock_);
   queue_.Clear();
 }
 
 
 MessageDispatchHelperThread::MessageDispatchHelperThread(Isolate* isolate)
     : Thread("v8:MsgDispHelpr"),
-      sem_(OS::CreateSemaphore(0)), mutex_(OS::CreateMutex()),
-      already_signalled_(false) {
+      isolate_(isolate), sem_(OS::CreateSemaphore(0)),
+      mutex_(OS::CreateMutex()), already_signalled_(false) {
 }
 
 
 MessageDispatchHelperThread::~MessageDispatchHelperThread() {
   delete mutex_;
   delete sem_;
 }
 
 
 void MessageDispatchHelperThread::Schedule() {
   {
     ScopedLock lock(mutex_);
     if (already_signalled_) {
       return;
     }
     already_signalled_ = true;
   }
   sem_->Signal();
 }
 
 
 void MessageDispatchHelperThread::Run() {
-  Isolate* isolate = Isolate::Current();
   while (true) {
     sem_->Wait();
     {
       ScopedLock lock(mutex_);
       already_signalled_ = false;
     }
     {
-      Locker locker(reinterpret_cast<v8::Isolate*>(isolate));
-      isolate->debugger()->CallMessageDispatchHandler();
+      Locker locker(reinterpret_cast<v8::Isolate*>(isolate_));
+      isolate_->debugger()->CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal