Fix a bunch of IWYU violators that don't include scoped_ptr.h

sync/internal_api/public/attachments/task_queue.h

 // Copyright 2014 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 SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_TASK_QUEUE_H_
 #define SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_TASK_QUEUE_H_
 
 #include <stddef.h>
+
 #include <deque>
 #include <set>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "net/base/backoff_entry.h"
 
 namespace syncer {
 
 // A queue that dispatches tasks, ignores duplicates, and provides backoff
@@ skipping 249 matching lines @@
 }
 
 template <typename T>
 bool TaskQueue<T>::ShouldDispatch() {
   return num_in_progress_ < kMaxConcurrentTasks && !queue_.empty();
 }
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_TASK_QUEUE_H_