A64: Synchronize with r16587.

src/platform/mutex.h

Index: src/platform/mutex.h
diff --git a/src/platform/mutex.h b/src/platform/mutex.h
index 19405424102c377130f08e071387d1c616e49ab7..ff519b9f0832fe24cdb1ae8e861f7203fd0be957 100644
--- a/src/platform/mutex.h
+++ b/src/platform/mutex.h
@@ -94,6 +94,22 @@ class Mutex V8_FINAL {
   int level_;
 #endif
 
+  V8_INLINE(void AssertHeldAndUnmark()) {
+#ifdef DEBUG
+    ASSERT_EQ(1, level_);
+    level_--;
+#endif
+  }
+
+  V8_INLINE(void AssertUnheldAndMark()) {
+#ifdef DEBUG
+    ASSERT_EQ(0, level_);
+    level_++;
+#endif
+  }
+
+  friend class ConditionVariable;
+
   DISALLOW_COPY_AND_ASSIGN(Mutex);
 };
 
@@ -214,8 +230,7 @@ class LockGuard V8_FINAL {
  private:
   Mutex* mutex_;
 
-  LockGuard(const LockGuard<Mutex>& other) V8_DELETE;
-  LockGuard<Mutex>& operator=(const LockGuard<Mutex>& other) V8_DELETE;
+  DISALLOW_COPY_AND_ASSIGN(LockGuard);
 };
 
 } }  // namespace v8::internal