Reduce CPU usage of download shelf UI. (both MD and pre-MD shelves)

chrome/browser/ui/views/download/download_item_view_md.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.
 //
 // A view that implements one download on the Download shelf.
 // Each DownloadItemViewMd contains an application icon, a text label
 // indicating the download's file name, a text label indicating the
 // download's status (such as the number of bytes downloaded so far)
 // and a button for canceling an in progress download, or opening
 // the completed download.
@@ skipping 195 matching lines @@
   // so that screenreaders can access the filename, status text, and
   // dangerous download warning message (if any).
   void UpdateAccessibleName();
 
   // Show/Hide/Reset |animation| based on the state transition specified by
   // |from| and |to|.
   void AnimateStateTransition(State from,
                               State to,
                               gfx::SlideAnimation* animation);
 
+  // Callback for |progress_timer_|.
+  void ProgressTimerFired();
+
   // Returns the base text color.
   SkColor GetTextColor();
 
   // Returns a slightly dimmed version of the base text color.
   SkColor GetDimmedTextColor();
 
   // The download shelf that owns us.
   DownloadShelfView* shelf_;
 
   // Elements of our particular download
@@ skipping 88 matching lines @@
   scoped_ptr<extensions::ExperienceSamplingEvent> sampling_event_;
 
   // Method factory used to delay reenabling of the item when opening the
   // downloaded file.
   base::WeakPtrFactory<DownloadItemViewMd> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadItemViewMd);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_DOWNLOAD_DOWNLOAD_ITEM_VIEW_MD_H_