Remove unneeded uses of logging.h in header files.

base/task.h

 // Copyright (c) 2006-2008 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 BASE_TASK_H_
 #define BASE_TASK_H_
 
-#include "base/logging.h"
 #include "base/non_thread_safe.h"
 #include "base/revocable_store.h"
 #include "base/tracked.h"
 #include "base/tuple.h"
 
 // Task ------------------------------------------------------------------------
 //
 // A task is a generic runnable thingy, usually used for running code on a
 // different thread or for scheduling future tasks off of the message loop.
 
@@ skipping 642 matching lines @@
   UnboundMethod(Method m, Params p) : m_(m), p_(p) {}
   void Run(T* obj) const {
     DispatchToMethod(obj, m_, p_);
   }
  private:
   Method m_;
   Params p_;
 };
 
 #endif  // BASE_TASK_H_