Add Ignition to about:flags.

gin/v8_initializer.cc

 // Copyright 2013 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 "gin/v8_initializer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/debug/alias.h"
+#include "base/feature_list.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/files/memory_mapped_file.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/rand_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
 #include "crypto/sha2.h"
+#include "gin/public/gin_features.h"
 
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
 #if defined(OS_ANDROID)
 #include "base/android/apk_assets.h"
 #endif
 #if defined(OS_MACOSX)
 #include "base/mac/foundation_util.h"
 #endif  // OS_MACOSX
 #include "base/path_service.h"
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
@@ skipping 380 matching lines @@
 
   if (IsolateHolder::kStrictMode == mode) {
     static const char use_strict[] = "--use_strict";
     v8::V8::SetFlagsFromString(use_strict, sizeof(use_strict) - 1);
   }
   if (IsolateHolder::kStableAndExperimentalV8Extras == v8_extras_mode) {
     static const char flag[] = "--experimental_extras";
     v8::V8::SetFlagsFromString(flag, sizeof(flag) - 1);
   }
 
+  if (base::FeatureList::IsEnabled(features::kV8Ignition)) {
+    std::string flag("--ignition");
+    v8::V8::SetFlagsFromString(flag.c_str(), static_cast<int>(flag.size()));
+  }
+
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
   v8::StartupData natives;
   natives.data = reinterpret_cast<const char*>(g_mapped_natives->data());
   natives.raw_size = static_cast<int>(g_mapped_natives->length());
   v8::V8::SetNativesDataBlob(&natives);
 
   if (g_mapped_snapshot != NULL) {
     v8::StartupData snapshot;
     snapshot.data = reinterpret_cast<const char*>(g_mapped_snapshot->data());
     snapshot.raw_size = static_cast<int>(g_mapped_snapshot->length());
@@ skipping 39 matching lines @@
 
 // static
 base::FilePath V8Initializer::GetSnapshotFilePath(bool abi_32_bit) {
   base::FilePath path;
   GetV8FilePath(abi_32_bit ? kSnapshotFileName32 : kSnapshotFileName64, &path);
   return path;
 }
 #endif  // defined(OS_ANDROID)
 
 }  // namespace gin