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

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 2e9ed9b77261a55a0255cf34486deceadd815fc3..5ff48bd16fa853c31edcf907c520dd223643ae1f 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -251,8 +251,8 @@
 #include "chrome/browser/media/webrtc_logging_handler_host.h"
 #endif
 
-using blink::WebWindowFeatures;
 using base::FileDescriptor;
+using blink::WebWindowFeatures;
 using content::AccessTokenStore;
 using content::BrowserChildProcessHostIterator;
 using content::BrowserThread;
@@ -666,6 +666,9 @@ void ChromeContentBrowserClient::RegisterProfilePrefs(
       prefs::kEnableHyperlinkAuditing,
       true,
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterListPref(
+      prefs::kEnableDeprecatedWebPlatformFeatures,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 // static
@@ -1609,6 +1612,18 @@ void ChromeContentBrowserClient::AppendExtraCommandLineSwitches(
         command_line->AppendSwitch(switches::kDisable3DAPIs);
       }
 
+      const base::ListValue* switches =
+          prefs->GetList(prefs::kEnableDeprecatedWebPlatformFeatures);
+      if (switches) {
+        // Enable any deprecated features that have been re-enabled by policy.
+        for (base::ListValue::const_iterator it = switches->begin();
+             it != switches->end(); ++it) {
+          std::string switch_to_enable;
+          if ((*it)->GetAsString(&switch_to_enable))
+            command_line->AppendSwitch(switch_to_enable);
+        }
+      }
+
       // Disable client-side phishing detection in the renderer if it is
       // disabled in the Profile preferences or the browser process.
       if (!prefs->GetBoolean(prefs::kSafeBrowsingEnabled) ||