Add Ignition to about:flags.

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 <stddef.h>
 #include <limits>
 #include <set>
 #include <utility>
 #include <vector>
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/path_service.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/platform_thread.h"
 #include "build/build_config.h"
 #include "chrome/common/child_process_logging.h"
+#include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/media/media_resource_provider.h"
 #include "chrome/common/net/net_resource_provider.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/resource_usage_reporter.mojom.h"
 #include "chrome/common/resource_usage_reporter_type_converters.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/renderer/content_settings_observer.h"
 #include "chrome/renderer/security_filter_peer.h"
@@ skipping 214 matching lines @@
   if (command_line.HasSwitch(switches::kJavaScriptHarmony)) {
     std::string flag("--harmony");
     v8::V8::SetFlagsFromString(flag.c_str(), static_cast<int>(flag.size()));
   }
 
   if (command_line.HasSwitch(switches::kEnableWasm)) {
     std::string flag("--expose-wasm");
     v8::V8::SetFlagsFromString(flag.c_str(), static_cast<int>(flag.size()));
   }
 
+  if (base::FeatureList::IsEnabled(features::kV8Ignition)) {
+    std::string flag("--ignition");
+    v8::V8::SetFlagsFromString(flag.c_str(), static_cast<int>(flag.size()));

[jochen (gone - plz use gerrit), 2016/03/30 16:13:34]

you could move this to gin/isolate_holder.cc - then it will be applied
everywhere

[Alexei Svitkine (slow), 2016/03/30 17:02:44]

Unfortunately, this is not possible currently due to http://crbug.com/599165

I'll be working on resolving that, but for now it can't be done from there.

+  }
+
   RenderThread* thread = RenderThread::Get();
   resource_delegate_.reset(new RendererResourceDelegate());
   thread->SetResourceDispatcherDelegate(resource_delegate_.get());
 
   thread->GetServiceRegistry()->AddService<ResourceUsageReporter>(
       base::Bind(CreateResourceUsageReporter, weak_factory_.GetWeakPtr()));
 
   // Configure modules that need access to resources.
   net::NetModule::SetResourceProvider(chrome_common_net::NetResourceProvider);
   media::SetLocalizedStringProvider(
@@ skipping 116 matching lines @@
 ChromeRenderProcessObserver::content_setting_rules() const {
   return &content_setting_rules_;
 }
 
 void ChromeRenderProcessObserver::OnFieldTrialGroupFinalized(
     const std::string& trial_name,
     const std::string& group_name) {
   content::RenderThread::Get()->Send(
       new ChromeViewHostMsg_FieldTrialActivated(trial_name));
 }