Revert of base: Remove using:: declaration from version.h header.

chrome/browser/extensions/extension_sync_data.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_EXTENSIONS_EXTENSION_SYNC_DATA_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SYNC_DATA_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 78 matching lines @@
   bool enabled() const { return enabled_; }
   bool supports_disable_reasons() const { return supports_disable_reasons_; }
   int disable_reasons() const { return disable_reasons_; }
   bool incognito_enabled() const { return incognito_enabled_; }
   bool remote_install() const { return remote_install_; }
   OptionalBoolean all_urls_enabled() const { return all_urls_enabled_; }
   bool installed_by_custodian() const { return installed_by_custodian_; }
 
   // Version-dependent properties (i.e., should be used only when the
   // version of the currently-installed extension matches |version|).
-  const base::Version& version() const { return version_; }
+  const Version& version() const { return version_; }
   const GURL& update_url() const { return update_url_; }
   // Used only for debugging.
   const std::string& name() const { return name_; }
 
   // Everything below is App-specific - only set for Apps, not Extensions.
 
   // These ordinals aren't necessarily valid. Some applications don't have
   // valid ordinals because they don't appear on the new tab page.
   const syncer::StringOrdinal& app_launch_ordinal() const {
     return app_launch_ordinal_;
@@ skipping 37 matching lines @@
   // |supports_disable_reasons_| is true if the optional |disable_reasons_| was
   // set to some value in the extension_specifics.proto. If not,
   // |disable_reasons_| is given a default value and |supports_disable_reasons_|
   // is false.
   bool supports_disable_reasons_;
   int disable_reasons_;
   bool incognito_enabled_;
   bool remote_install_;
   OptionalBoolean all_urls_enabled_;
   bool installed_by_custodian_;
-  base::Version version_;
+  Version version_;
   GURL update_url_;
   std::string name_;
 
   // App-specific fields.
   syncer::StringOrdinal app_launch_ordinal_;
   syncer::StringOrdinal page_ordinal_;
   extensions::LaunchType launch_type_;
   std::string bookmark_app_url_;
   std::string bookmark_app_description_;
   std::string bookmark_app_icon_color_;
   std::vector<LinkedAppIconInfo> linked_icons_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SYNC_DATA_H_