[BlobAsync] Renderer support for blob file writing.

content/child/blob_storage/blob_message_filter.h

 // Copyright 2015 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 CONTENT_CHILD_BLOB_STORAGE_BLOB_MESSAGE_FILTER_H_
 #define CONTENT_CHILD_BLOB_STORAGE_BLOB_MESSAGE_FILTER_H_
 
 #include <stddef.h>
 
+#include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/shared_memory.h"
 #include "ipc/ipc_platform_file.h"
 #include "ipc/message_filter.h"
 #include "storage/common/blob_storage/blob_storage_constants.h"
 
+namespace base {
+class TaskRunner;
+}
+
 namespace IPC {
 class Sender;
 class Message;
 }
 
 namespace storage {
 struct BlobItemBytesRequest;
+struct BlobItemBytesResponse;
 }
 
 namespace content {
 
 // MessageFilter that handles Blob IPCs and delegates them to the
 // BlobTransportController singleton. Created on the render thread, and then
 // operated on by the IO thread.
 class BlobMessageFilter : public IPC::MessageFilter {
  public:
-  BlobMessageFilter();
+  BlobMessageFilter(scoped_refptr<base::TaskRunner> file_runner);
 
+  void OnChannelClosing() override;
   void OnFilterAdded(IPC::Sender* sender) override;
   bool OnMessageReceived(const IPC::Message& message) override;
   bool GetSupportedMessageClasses(
       std::vector<uint32_t>* supported_message_classes) const override;
 
  protected:
   ~BlobMessageFilter() override;
 
  private:
   void OnRequestMemoryItem(
       const std::string& uuid,
       const std::vector<storage::BlobItemBytesRequest>& requests,
       std::vector<base::SharedMemoryHandle> memory_handles,
       const std::vector<IPC::PlatformFileForTransit>& file_handles);
 
   void OnCancelBuildingBlob(const std::string& uuid,
                             storage::IPCBlobCreationCancelCode code);
 
   void OnDoneBuildingBlob(const std::string& uuid);
 
   IPC::Sender* sender_;
+  scoped_refptr<base::TaskRunner> file_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(BlobMessageFilter);
 };
 
 }  // namespace content
 #endif  // CONTENT_CHILD_BLOB_STORAGE_BLOB_MESSAGE_FILTER_H_