Add a policy to re-enable deprecated web platform features.

chrome/common/pref_names.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.
 
 // Constants for the names of various preferences, for easier changing.
 
 #ifndef CHROME_COMMON_PREF_NAMES_H_
 #define CHROME_COMMON_PREF_NAMES_H_
 
 #include <stddef.h>
@@ skipping 34 matching lines @@
 extern const char kApplicationLocale[];
 #if defined(OS_CHROMEOS)
 extern const char kApplicationLocaleBackup[];
 extern const char kApplicationLocaleAccepted[];
 extern const char kOwnerLocale[];
 #endif
 
 extern const char kDefaultCharset[];
 extern const char kAcceptLanguages[];
 extern const char kStaticEncodings[];
+extern const char kEnableDeprecatedWebPlatformFeatures[];
 extern const char kWebKitCommonScript[];
 extern const char kWebKitStandardFontFamily[];
 extern const char kWebKitFixedFontFamily[];
 extern const char kWebKitSerifFontFamily[];
 extern const char kWebKitSansSerifFontFamily[];
 extern const char kWebKitCursiveFontFamily[];
 extern const char kWebKitFantasyFontFamily[];
 extern const char kWebKitPictographFontFamily[];
 
 // ISO 15924 four-letter script codes that per-script font prefs are supported
@@ skipping 813 matching lines @@
 
 #if defined(OS_ANDROID)
 extern const char kPartnerBookmarkMappings[];
 #endif
 
 extern const char kQuickCheckEnabled[];
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_