When an Isolate is configured to use lockers, foreground tasks need to lock

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 <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ skipping 23 matching lines @@
     : 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());
   params.array_buffer_allocator = allocator;
   isolate_ = v8::Isolate::New(params);
-  isolate_data_.reset(new PerIsolateData(isolate_, allocator));
+  isolate_data_.reset(new PerIsolateData(isolate_, allocator, access_mode));
   isolate_memory_dump_provider_.reset(new V8IsolateMemoryDumpProvider(this));
 #if defined(OS_WIN)
   {
     void* code_range;
     size_t size;
     isolate_->GetCodeRange(&code_range, &size);
     Debug::CodeRangeCreatedCallback callback =
         DebugImpl::GetCodeRangeCreatedCallback();
     if (code_range && size && callback)
       callback(code_range, size);
@@ skipping 42 matching lines @@
   task_observer_.reset();
 }
 
 void IsolateHolder::EnableIdleTasks(
     std::unique_ptr<V8IdleTaskRunner> idle_task_runner) {
   DCHECK(isolate_data_.get());
   isolate_data_->EnableIdleTasks(std::move(idle_task_runner));
 }
 
 }  // namespace gin