Deinline even more destructors.

chrome/browser/dom_ui/fileicon_source.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 CHROME_BROWSER_DOM_UI_FILEICON_SOURCE_H_
 #define CHROME_BROWSER_DOM_UI_FILEICON_SOURCE_H_
 #pragma once
 
 #include <string>
 
 #include "chrome/browser/dom_ui/chrome_url_data_manager.h"
 #include "chrome/browser/icon_manager.h"
 
 class GURL;
 class RefCountedBytes;
 
 // FileIconSource is the gateway between network-level chrome:
 // requests for favicons and the history backend that serves these.
 class FileIconSource : public ChromeURLDataManager::DataSource {
  public:
   explicit FileIconSource();
 
   // Called when the network layer has requested a resource underneath
   // the path we registered.
   virtual void StartDataRequest(const std::string& path,
                                 bool is_off_the_record,
                                 int request_id);
 
-  virtual std::string GetMimeType(const std::string&) const {
-    // Rely on image decoder inferring the correct type.
-    return std::string();
-  }
+  virtual std::string GetMimeType(const std::string&) const;
 
   // Called when favicon data is available from the history backend.
   void OnFileIconDataAvailable(
       IconManager::Handle request_handle,
       SkBitmap* icon);
 
  private:
   virtual ~FileIconSource();
 
   CancelableRequestConsumerT<int, 0> cancelable_consumer_;
 
   // Raw PNG representation of the favicon to show when the favicon
   // database doesn't have a favicon for a webpage.
   scoped_refptr<RefCountedBytes> default_favicon_;
 
   DISALLOW_COPY_AND_ASSIGN(FileIconSource);
 };
 #endif  // CHROME_BROWSER_DOM_UI_FILEICON_SOURCE_H_