Simplify implementation of Mutex.

test/cctest/test-lock.cc

Index: test/cctest/test-lock.cc
diff --git a/test/cctest/test-lock.cc b/test/cctest/test-lock.cc
index d4387d0f906787ebf12195ad1a789448cfde5b3a..81f7771c7d35121ff790c5398786785bab70d06c 100644
--- a/test/cctest/test-lock.cc
+++ b/test/cctest/test-lock.cc
@@ -40,28 +40,18 @@ using namespace ::v8::internal;
 
 // Simple test of locking logic
 TEST(Simple) {
-  Mutex* mutex = OS::CreateMutex();
-  CHECK_EQ(0, mutex->Lock());  // acquire the lock with the right token
-  CHECK_EQ(0, mutex->Unlock());  // can unlock with the right token
-  delete mutex;
-}
-
-
-TEST(MultiLock) {
-  Mutex* mutex = OS::CreateMutex();
-  CHECK_EQ(0, mutex->Lock());
-  CHECK_EQ(0, mutex->Unlock());
-  delete mutex;
+  Mutex mutex;
+  mutex.Lock();  // acquire the lock with the right token
+  mutex.Unlock();  // can unlock with the right token
 }
 
 
 TEST(ShallowLock) {
-  Mutex* mutex = OS::CreateMutex();
-  CHECK_EQ(0, mutex->Lock());
-  CHECK_EQ(0, mutex->Unlock());
-  CHECK_EQ(0, mutex->Lock());
-  CHECK_EQ(0, mutex->Unlock());
-  delete mutex;
+  Mutex mutex;
+  mutex.Lock();
+  mutex.Unlock();
+  mutex.Lock();
+  mutex.Unlock();
 }