Reverse the embedded-shared-worker flag to turn the feature on by default.

content/browser/worker_host/worker_service_impl.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 "content/browser/worker_host/worker_service_impl.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 218 matching lines @@
 }
 
 WorkerService* WorkerService::GetInstance() {
   if (EmbeddedSharedWorkerEnabled())
     return SharedWorkerServiceImpl::GetInstance();
   else
     return WorkerServiceImpl::GetInstance();
 }
 
 bool WorkerService::EmbeddedSharedWorkerEnabled() {
-  static bool enabled = CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kEnableEmbeddedSharedWorker);
-  return enabled;
+  static bool disabled = CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kDisableEmbeddedSharedWorker);
+  return !disabled;
 }
 
 WorkerServiceImpl* WorkerServiceImpl::GetInstance() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   return Singleton<WorkerServiceImpl>::get();
 }
 
 WorkerServiceImpl::WorkerServiceImpl()
     : priority_setter_(new WorkerPrioritySetter()),
       next_worker_route_id_(0) {
@@ skipping 339 matching lines @@
          instance_iter != iter->mutable_instances().end();
          ++instance_iter) {
       if (instance_iter->Matches(url, name, partition, resource_context))
         return &(*instance_iter);
     }
   }
   return NULL;
 }
 
 }  // namespace content