blink: Cleanup class forward declarations

third_party/WebKit/Source/platform/scheduler/CancellableTaskFactory.h

 // Copyright 2015 The Chromium 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 CancellableTaskFactory_h
 #define CancellableTaskFactory_h
 
 #include "platform/PlatformExport.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebTaskRunner.h"
@@ skipping 21 matching lines @@
 //       WTF::bind(wrapPersistent(foo), &Foo::bar);
 //   RefPtr<TaskHandle> handle =
 //       task_runner->postCancellableTask(BLINK_FROM_HERE, std::move(task));
 //   handle->cancel();
 //
 // Note that the task is not automatically cancelled on the scope out of
 // RefPtr<TaskHandle>, since the wrapped task has a reference to the TaskHandle.
 
 namespace blink {
 
-class TraceLocation;
-
 class PLATFORM_EXPORT CancellableTaskFactory {
   WTF_MAKE_NONCOPYABLE(CancellableTaskFactory);
   USING_FAST_MALLOC(CancellableTaskFactory);
 
  public:
   // A pair of mutually exclusive factory methods are provided for constructing
   // a CancellableTaskFactory, one for when a Oilpan heap object owns a
   // CancellableTaskFactory, and one when that owning object isn't controlled
   // by Oilpan.
   //
@@ skipping 56 matching lines @@
     WeakPtr<CancellableTaskFactory> m_weakPtr;
   };
 
   std::unique_ptr<WTF::Closure> m_closure;
   WeakPtrFactory<CancellableTaskFactory> m_weakPtrFactory;
 };
 
 }  // namespace blink
 
 #endif  // CancellableTaskFactory_h