Misc cleanups in Drive code.

chrome/browser/chromeos/drive/drive_feed_loader_observer.h

 // Copyright (c) 2012 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 CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FEED_LOADER_OBSERVER_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FEED_LOADER_OBSERVER_H_
 
-#include <string>
-
 namespace base {
 class FilePath;
 }
 
 namespace drive {
 
 // Interface for classes that need to observe events from DriveFeedLoader.
 // All events are notified on UI thread.
 class DriveFeedLoaderObserver {
  public:
@@ skipping 12 matching lines @@
   virtual void OnFeedFromServerLoaded() {
   }
 
  protected:
   virtual ~DriveFeedLoaderObserver() {}
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FEED_LOADER_OBSERVER_H_