Remove V8_WARN_UNUSED_RESULT for simple getters.

src/platform/mutex.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 63 matching lines @@
   // successfully locked.
   bool TryLock() V8_WARN_UNUSED_RESULT;
 
   // The implementation-defined native handle type.
 #if V8_OS_POSIX
   typedef pthread_mutex_t NativeHandle;
 #elif V8_OS_WIN
   typedef CRITICAL_SECTION NativeHandle;
 #endif
 
-  NativeHandle& native_handle() V8_WARN_UNUSED_RESULT {
+  NativeHandle& native_handle() {
     return native_handle_;
   }
-  const NativeHandle& native_handle() const V8_WARN_UNUSED_RESULT {
+  const NativeHandle& native_handle() const {
     return native_handle_;
   }
 
  private:
   NativeHandle native_handle_;
 #ifdef DEBUG
   int level_;
 #endif
 
   V8_INLINE(void AssertHeldAndUnmark()) {
@@ skipping 72 matching lines @@
   // undefined.
   void Unlock();
 
   // Tries to lock the given mutex. Returns whether the mutex was
   // successfully locked.
   bool TryLock() V8_WARN_UNUSED_RESULT;
 
   // The implementation-defined native handle type.
   typedef Mutex::NativeHandle NativeHandle;
 
-  NativeHandle& native_handle() V8_WARN_UNUSED_RESULT {
+  NativeHandle& native_handle() {
     return native_handle_;
   }
-  const NativeHandle& native_handle() const V8_WARN_UNUSED_RESULT {
+  const NativeHandle& native_handle() const {
     return native_handle_;
   }
 
  private:
   NativeHandle native_handle_;
 #ifdef DEBUG
   int level_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(RecursiveMutex);
@@ skipping 35 matching lines @@
 
  private:
   Mutex* mutex_;
 
   DISALLOW_COPY_AND_ASSIGN(LockGuard);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_MUTEX_H_