Move glue code of blob channel to blimp_client_context_impl.

blimp/client/core/compositor/blob_channel_feature.h

+// Copyright 2016 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 BLIMP_CLIENT_CORE_COMPOSITOR_BLOB_CHANNEL_FEATURE_H_
+#define BLIMP_CLIENT_CORE_COMPOSITOR_BLOB_CHANNEL_FEATURE_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "blimp/client/core/compositor/blob_image_serialization_processor.h"
+#include "blimp/client/core/compositor/decoding_image_generator.h"
+#include "blimp/net/blimp_message_processor.h"
+
+namespace blimp {
+
+class BlobChannelReceiver;
+
+namespace client {
+
+// BlobChannelFeature processes incoming BlobChannel message from the engine and
+// holds the cache of Blob payloads.
+class BlobChannelFeature : public BlimpMessageProcessor {
+ public:
+  explicit BlobChannelFeature(
+      BlobImageSerializationProcessor::ErrorDelegate* delegate);
+  ~BlobChannelFeature() override;
+
+ protected:
+  // The receiver that does the actual blob processing, protected for test.
+  std::unique_ptr<BlobChannelReceiver> blob_receiver_;
+
+ private:
+  // BlimpMessageProcessor implementation.
+  void ProcessMessage(std::unique_ptr<BlimpMessage> message,
+                      const net::CompletionCallback& callback) override;
+
+  // Receives blob BlimpMessages and relays blob data to BlobChannelReceiver.
+  // Owned by BlobChannelReceiver, therefore stored as a raw pointer here.
+  BlimpMessageProcessor* incoming_msg_processor_ = nullptr;
+
+  // Retrieves and decodes image data from |blob_receiver_|. Must outlive
+  // |blob_receiver_|.
+  BlobImageSerializationProcessor blob_image_processor_;
+
+  DISALLOW_COPY_AND_ASSIGN(BlobChannelFeature);
+};
+
+}  // namespace client
+}  // namespace blimp
+
+#endif  // BLIMP_CLIENT_CORE_COMPOSITOR_BLOB_CHANNEL_FEATURE_H_