Adding field to tell if gin::IsolateHolder needs lock to be accessed.

gin/isolate_holder.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/public/isolate_holder.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/sys_info.h"
 #include "gin/debug_impl.h"
 #include "gin/function_template.h"
 #include "gin/per_isolate_data.h"
 #include "gin/run_microtasks_observer.h"
 #include "gin/v8_initializer.h"
 
 namespace gin {
 
 namespace {
 v8::ArrayBuffer::Allocator* g_array_buffer_allocator = nullptr;
 }  // namespace
 
-IsolateHolder::IsolateHolder() {
+IsolateHolder::IsolateHolder() : IsolateHolder(AccessMode::kSingleThread) {
+}
+
+IsolateHolder::IsolateHolder(AccessMode access_mode)
+    : access_mode_(access_mode) {
   v8::ArrayBuffer::Allocator* allocator = g_array_buffer_allocator;
   CHECK(allocator) << "You need to invoke gin::IsolateHolder::Initialize first";
   v8::Isolate::CreateParams params;
   params.entry_hook = DebugImpl::GetFunctionEntryHook();
   params.code_event_handler = DebugImpl::GetJitCodeEventHandler();
   params.constraints.ConfigureDefaults(base::SysInfo::AmountOfPhysicalMemory(),
                                        base::SysInfo::AmountOfVirtualMemory());
   isolate_ = v8::Isolate::New(params);
   isolate_data_.reset(new PerIsolateData(isolate_, allocator));
 #if defined(OS_WIN)
@@ skipping 42 matching lines @@
   base::MessageLoop::current()->AddTaskObserver(task_observer_.get());
 }
 
 void IsolateHolder::RemoveRunMicrotasksObserver() {
   DCHECK(task_observer_.get());
   base::MessageLoop::current()->RemoveTaskObserver(task_observer_.get());
   task_observer_.reset();
 }
 
 }  // namespace gin