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

chrome/browser/browsing_data_helper.cc

 // 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.
 
 #include "chrome/browser/browsing_data_helper.h"
 
 #include "base/command_line.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/child_process_security_policy.h"
 #include "googleurl/src/gurl.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
 
 // Static
-bool BrowsingDataHelper::IsValidScheme(const std::string& scheme) {
+bool BrowsingDataHelper::IsWebScheme(const std::string& scheme) {
   // Special-case `file://` scheme iff cookies and site data are enabled via
   // the `--allow-file-cookies` CLI flag.
   if (scheme == chrome::kFileScheme) {
     return CommandLine::ForCurrentProcess()->HasSwitch(
         switches::kEnableFileCookies);
 
   // Otherwise, all "web safe" schemes are valid, except `chrome-extension://`
   // and `chrome-devtools://`.
   } else {
     content::ChildProcessSecurityPolicy* policy =
         content::ChildProcessSecurityPolicy::GetInstance();
     return (policy->IsWebSafeScheme(scheme) &&
-            scheme != chrome::kChromeDevToolsScheme &&
-            scheme != chrome::kExtensionScheme);
+            !BrowsingDataHelper::IsExtensionScheme(scheme) &&
+            scheme != chrome::kChromeDevToolsScheme);
   }
 }
 
 // Static
-bool BrowsingDataHelper::IsValidScheme(const WebKit::WebString& scheme) {
-  return BrowsingDataHelper::IsValidScheme(UTF16ToUTF8(scheme));
+bool BrowsingDataHelper::IsWebScheme(const WebKit::WebString& scheme) {
+  return BrowsingDataHelper::IsWebScheme(UTF16ToUTF8(scheme));
 }
 
 // Static
-bool BrowsingDataHelper::HasValidScheme(const GURL& origin) {
-  return BrowsingDataHelper::IsValidScheme(origin.scheme());
+bool BrowsingDataHelper::HasWebScheme(const GURL& origin) {
+  return BrowsingDataHelper::IsWebScheme(origin.scheme());
 }
+
+// Static
+bool BrowsingDataHelper::IsExtensionScheme(const std::string& scheme) {
+  return scheme == chrome::kExtensionScheme;
+}
+
+// Static
+bool BrowsingDataHelper::IsExtensionScheme(const WebKit::WebString& scheme) {
+  return BrowsingDataHelper::IsExtensionScheme(UTF16ToUTF8(scheme));
+}
+
+// Static
+bool BrowsingDataHelper::HasExtensionScheme(const GURL& origin) {
+  return BrowsingDataHelper::IsExtensionScheme(origin.scheme());
+}