Introduce SharedMemoryDataConsumerHandle.

content/child/shared_memory_data_consumer_handle.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_SHARED_MEMORY_DATA_CONSUMER_HANDLE_H_
+#define CONTENT_CHILD_SHARED_MEMORY_DATA_CONSUMER_HANDLE_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/common/content_export.h"
+#include "content/public/child/request_peer.h"
+#include "third_party/WebKit/public/platform/WebDataConsumerHandle.h"
+
+namespace content {
+
+// This class is a WebDataConsumerHandle that accepts RequestPeer::ReceivedData.
+// TODO(yhirano): Currently this only works on a single thread. Make this class
+// work with a multi thread environment.
+class CONTENT_EXPORT SharedMemoryDataConsumerHandle final
+    : public NON_EXPORTED_BASE(blink::WebDataConsumerHandle) {
+ private:
+  class Context;
+
+ public:
+  enum BackpressureMode {
+    kApplyBackpressure,
+    kDoNotApplyBackpressure,
+  };
+
+  class CONTENT_EXPORT Writer final {
+   public:
+    Writer(const scoped_refptr<Context>& context, BackpressureMode mode);
+    ~Writer();
+    void AddData(scoped_ptr<RequestPeer::ReceivedData> data);
+    void Close();
+
+   private:
+    scoped_refptr<Context> context_;
+    BackpressureMode mode_;
+
+    DISALLOW_COPY_AND_ASSIGN(Writer);
+  };
+
+  SharedMemoryDataConsumerHandle(BackpressureMode mode,
+                                 scoped_ptr<Writer>* writer);
+  virtual ~SharedMemoryDataConsumerHandle();
+
+  virtual Result read(void* data, size_t size, Flags flags, size_t* readSize);
+  virtual Result beginRead(const void** buffer, Flags flags, size_t* available);
+  virtual Result endRead(size_t readSize);
+  virtual void registerClient(Client* client);
+  virtual void unregisterClient();
+
+ private:
+  scoped_refptr<Context> context_;
+
+  DISALLOW_COPY_AND_ASSIGN(SharedMemoryDataConsumerHandle);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_CHILD_SHARED_MEMORY_DATA_CONSUMER_HANDLE_H_