Renaming `BrowsingDataHelper::IsValidScheme`, as it's poorly descriptive.

chrome/browser/browsing_data_helper.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.
 
 // Defines methods relevant to all code that wants to work with browsing data.
 
 #ifndef CHROME_BROWSER_BROWSING_DATA_HELPER_H_
 #define CHROME_BROWSER_BROWSING_DATA_HELPER_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 
 namespace WebKit {
 class WebString;
 }
 
 class GURL;
 
 class BrowsingDataHelper {
  public:
   // Returns true iff the provided scheme is (really) web safe, and suitable
   // for treatment as "browsing data". This relies on the definition of web safe
   // in ChildProcessSecurityPolicy, but excluding schemes like
   // `chrome-extension`.
-  static bool IsValidScheme(const std::string& scheme);
-  static bool IsValidScheme(const WebKit::WebString& scheme);
-  static bool HasValidScheme(const GURL& origin);
+  static bool IsWebScheme(const std::string& scheme);
+  static bool IsWebScheme(const WebKit::WebString& scheme);
+  static bool HasWebScheme(const GURL& origin);
+
+  // Returns true iff the provided scheme is an extension.
+  static bool IsExtensionScheme(const std::string& scheme);
+  static bool IsExtensionScheme(const WebKit::WebString& scheme);
+  static bool HasExtensionScheme(const GURL& origin);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(BrowsingDataHelper);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_HELPER_H_