[iwyu] Include handles.h less.

src/futex-emulation.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_FUTEX_EMULATION_H_
 #define V8_FUTEX_EMULATION_H_
 
 #include <stdint.h>
 
 #include "src/allocation.h"
 #include "src/base/atomicops.h"
 #include "src/base/lazy-instance.h"
 #include "src/base/macros.h"
 #include "src/base/platform/condition-variable.h"
 #include "src/base/platform/mutex.h"
-#include "src/handles.h"
 
 // Support for emulating futexes, a low-level synchronization primitive. They
 // are natively supported by Linux, but must be emulated for other platforms.
 // This library emulates them on all platforms using mutexes and condition
 // variables for consistency.
 //
 // This is used by the Futex API defined in the SharedArrayBuffer draft spec,
 // found here: https://github.com/tc39/ecmascript_sharedmem
 
 namespace v8 {
 
 namespace base {
 class TimeDelta;
 }  // base
 
 namespace internal {
 
+template <typename T>
+class Handle;
 class Isolate;
 class JSArrayBuffer;
 
 class FutexWaitListNode {
  public:
   FutexWaitListNode()
       : prev_(nullptr),
         next_(nullptr),
         backing_store_(nullptr),
         wait_addr_(0),
@@ skipping 61 matching lines @@
  private:
   friend class FutexWaitListNode;
 
   static base::LazyMutex mutex_;
   static base::LazyInstance<FutexWaitList>::type wait_list_;
 };
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_FUTEX_EMULATION_H_