Revert the latest set of platform changes.

test/cctest/test-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 4696 matching lines @@
  private:
   int num_threads_;
   int num_blocked_;
   v8::internal::Mutex* lock_;
   v8::internal::Semaphore* sem_;
   bool invalid_;
 };
 
 ThreadBarrier::ThreadBarrier(int num_threads)
     : num_threads_(num_threads), num_blocked_(0) {
-  lock_ = new v8::internal::Mutex;
+  lock_ = OS::CreateMutex();
   sem_ = OS::CreateSemaphore(0);
   invalid_ = false;  // A barrier may only be used once.  Then it is invalid.
 }
 
 
 // Do not call, due to race condition with Wait().
 // Could be resolved with Pthread condition variables.
 ThreadBarrier::~ThreadBarrier() {
   lock_->Lock();
   delete lock_;
@@ skipping 2869 matching lines @@
 TEST(LiveEditDisabled) {
   v8::internal::FLAG_allow_natives_syntax = true;
   LocalContext env;
   v8::HandleScope scope(env->GetIsolate());
   v8::Debug::SetLiveEditEnabled(false);
   CompileRun("%LiveEditCompareStrings('', '')");
 }
 
 
 #endif  // ENABLE_DEBUGGER_SUPPORT