Refactor unit tests for the base library to use GTest.

test/cctest/test-threads.cc

 // Copyright 2008 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 157 matching lines @@
     refs.Add(i::ThreadId::Invalid());
   }
   prev->Start();
   for (int i = 0; i < kNThreads; i++) {
     semaphore.Wait();
   }
   for (int i = 0; i < kNThreads; i++) {
     delete threads[i];
   }
 }
-
-
-class ThreadC : public v8::base::Thread {
- public:
-  ThreadC() : Thread("ThreadC") { }
-  void Run() {
-    Join();
-  }
-};
-
-
-TEST(ThreadJoinSelf) {
-  ThreadC thread;
-  thread.Start();
-  thread.Join();
-}