Support DataSaver for SharedWorker

third_party/WebKit/Source/core/frame/Settings.json5

 {
   // Defines properties which are available on the Settings object.
   //
   // Please think carefully before adding a new Setting.  Some questions to
   // consider are:
   // - Should this be a RuntimeEnabledFeature instead? Settings are for things
   //   which we support either values of at runtime.  Features are set at renderer
   //   process startup and are never changed. Features also tend to be set to a
   //   value based on the platform or the stability of the code in question, where
   //   as settings both codepaths need to be stable.
@@ skipping 548 matching lines @@
       invalidate: "ViewportDescription",
     },
 
     {
       name: "dnsPrefetchingEnabled",
       initial: false,
       invalidate: "DNSPrefetching",
     },
 
     {
-      name: "dataSaverEnabled",
-      initial: false,
+      name: "dataSaverFlag",
+      initial: "WebDataSaverFlag::kDisabled",
+      type: "WebDataSaverFlag",
     },
 
     // Clients that execute script should call ExecutionContext::canExecuteScripts()
     // instead of this function. ExecutionContext::canExecuteScripts() checks the
     // HTML sandbox, plugin sandboxing, and other important details.
     {
       name: "scriptEnabled",
       initial: false,
     },
 
@@ skipping 338 matching lines @@
     },
 
     // Defines the autoplay policy to use.
     {
       name: "autoplayPolicy",
       type: "AutoplayPolicy::Type",
       initial: "AutoplayPolicy::Type::kNoUserGestureRequired",
     },
   ],
 }