gin: Make it possible to use gin array buffers when running on top of blink

gin/per_isolate_data.h

 // 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.
 
 #ifndef GIN_PER_ISOLATE_DATA_H_
 #define GIN_PER_ISOLATE_DATA_H_
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "gin/gin_export.h"
 #include "gin/public/wrapper_info.h"
 #include "v8/include/v8.h"
 
 namespace gin {
 
 // There is one instance of PerIsolateData per v8::Isolate managed by Gin. This
 // class stores all the Gin-related data that varies per isolate.
 class GIN_EXPORT PerIsolateData {
  public:
-  explicit PerIsolateData(v8::Isolate* isolate);
+  PerIsolateData(v8::Isolate* isolate, v8::ArrayBuffer::Allocator* allocator);
   ~PerIsolateData();
 
   static PerIsolateData* From(v8::Isolate* isolate);
 
   // Each isolate is associated with a collection of v8::ObjectTemplates and
   // v8::FunctionTemplates. Typically these template objects are created
   // lazily.
   void SetObjectTemplate(WrapperInfo* info,
                          v8::Local<v8::ObjectTemplate> object_template);
   void SetFunctionTemplate(WrapperInfo* info,
                            v8::Local<v8::FunctionTemplate> function_template);
 
   // These are low-level functions for retrieving object or function templates
   // stored in this object. Because these templates are often created lazily,
   // most clients should call higher-level functions that know how to populate
   // these templates if they haven't already been created.
   v8::Local<v8::ObjectTemplate> GetObjectTemplate(WrapperInfo* info);
   v8::Local<v8::FunctionTemplate> GetFunctionTemplate(WrapperInfo* info);
 
   v8::Isolate* isolate() { return isolate_; }
+  v8::ArrayBuffer::Allocator* allocator() { return allocator_; }
 
  private:
   typedef std::map<
       WrapperInfo*, v8::Eternal<v8::ObjectTemplate> > ObjectTemplateMap;
   typedef std::map<
       WrapperInfo*, v8::Eternal<v8::FunctionTemplate> > FunctionTemplateMap;
 
   // PerIsolateData doesn't actually own |isolate_|. Instead, the isolate is
   // owned by the IsolateHolder, which also owns the PerIsolateData.
   v8::Isolate* isolate_;
+  v8::ArrayBuffer::Allocator* allocator_;
   ObjectTemplateMap object_templates_;
   FunctionTemplateMap function_templates_;
 
   DISALLOW_COPY_AND_ASSIGN(PerIsolateData);
 };
 
 }  // namespace gin
 
 #endif  // GIN_PER_ISOLATE_DATA_H_