[gin] Add a v8::Platform implementation to allow for v8 posting tasks

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/rand_util.h"
 #include "base/sys_info.h"
 #include "gin/array_buffer.h"
 #include "gin/function_template.h"
 #include "gin/per_isolate_data.h"
+#include "gin/public/v8_platform.h"
 
 namespace gin {
 
 namespace {
 
 bool GenerateEntropy(unsigned char* buffer, size_t amount) {
   base::RandBytes(buffer, amount);
   return true;
 }
 
 
 void EnsureV8Initialized(bool gin_managed) {
   static bool v8_is_initialized = false;
   static bool v8_is_gin_managed = false;
   if (v8_is_initialized) {
     CHECK_EQ(v8_is_gin_managed, gin_managed);
     return;
   }
   v8_is_initialized = true;
   v8_is_gin_managed = gin_managed;
   if (!gin_managed)
     return;
 
+  v8::V8::InitializePlatform(V8Platform::Get());
   v8::V8::SetArrayBufferAllocator(ArrayBufferAllocator::SharedInstance());
   static const char v8_flags[] = "--use_strict --harmony";
   v8::V8::SetFlagsFromString(v8_flags, sizeof(v8_flags) - 1);
   v8::V8::SetEntropySource(&GenerateEntropy);
   v8::V8::Initialize();
 }
 
 }  // namespace
 
 IsolateHolder::IsolateHolder()
@@ skipping 20 matching lines @@
     isolate_->Dispose();
 }
 
 void IsolateHolder::Init(v8::ArrayBuffer::Allocator* allocator) {
   v8::Isolate::Scope isolate_scope(isolate_);
   v8::HandleScope handle_scope(isolate_);
   isolate_data_.reset(new PerIsolateData(isolate_, allocator));
 }
 
 }  // namespace gin