Move libplatform files into v8::platform namespace

test/cctest/test-libplatform.h

 // Copyright 2013 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 15 matching lines @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef TEST_LIBPLATFORM_H_
 #define TEST_LIBPLATFORM_H_
 
 #include "src/v8.h"
 
 #include "test/cctest/cctest.h"
 
 using namespace v8::internal;
+using namespace v8::platform;
 
 class TaskCounter {
  public:
   TaskCounter() : counter_(0) {}
   ~TaskCounter() { CHECK_EQ(0, counter_); }
 
   int GetCount() const {
     v8::base::LockGuard<v8::base::Mutex> guard(&lock_);
     return counter_;
   }
@@ skipping 65 matching lines @@
   }
 
  private:
   v8::base::Semaphore semaphore_;
   v8::Task* task_;
 
   DISALLOW_COPY_AND_ASSIGN(TestWorkerThread);
 };
 
 #endif  // TEST_LIBPLATFORM_H_