Let --js-flags work when Harmony is enabled in about:flags (reland)

chrome/renderer/chrome_render_process_observer.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/renderer/chrome_render_process_observer.h"
 
 #include <limits>
 #include <vector>
 
 #include "base/allocator/allocator_extension.h"
@@ skipping 246 matching lines @@
       webkit_initialized_(false) {
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
 #if defined(ENABLE_AUTOFILL_DIALOG)
   WebRuntimeFeatures::enableRequestAutocomplete(true);
 #endif
 
   if (command_line.HasSwitch(switches::kEnableShowModalDialog))
     WebRuntimeFeatures::enableShowModalDialog(true);
 
+  if (command_line.HasSwitch(switches::kJavaScriptHarmony)) {
+    std::string flag("--harmony");
+    v8::V8::SetFlagsFromString(flag.c_str(), static_cast<int>(flag.size()));
+  }
+
   RenderThread* thread = RenderThread::Get();
   resource_delegate_.reset(new RendererResourceDelegate());
   thread->SetResourceDispatcherDelegate(resource_delegate_.get());
 
   // Configure modules that need access to resources.
   net::NetModule::SetResourceProvider(chrome_common_net::NetResourceProvider);
 
 #if defined(OS_WIN)
   // Need to patch a few functions for font loading to work correctly.
   base::FilePath pdf;
@@ skipping 92 matching lines @@
 }
 
 void ChromeRenderProcessObserver::OnGetV8HeapStats() {
   HeapStatisticsCollector::Instance()->InitiateCollection();
 }
 
 const RendererContentSettingRules*
 ChromeRenderProcessObserver::content_setting_rules() const {
   return &content_setting_rules_;
 }