service worker: Refactor blob reading out of ServiceWorkerURLRequestJob

content/browser/service_worker/service_worker_blob_reader.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 CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_BLOB_READER_H_
+#define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_BLOB_READER_H_
+
+#include <memory>
+
+#include "content/browser/service_worker/service_worker_url_request_job.h"
+#include "net/base/io_buffer.h"
+#include "net/url_request/url_request.h"
+
+namespace content {
+
+// Reads a blob response for ServiceWorkerURLRequestJob.
+// Owned by ServiceWorkerURLRequestJob.
+class ServiceWorkerBlobReader : public net::URLRequest::Delegate {
+ public:
+  explicit ServiceWorkerBlobReader(ServiceWorkerURLRequestJob* owner);
+  ~ServiceWorkerBlobReader() override;
+
+  // Starts reading the blob. owner_->OnResponseStarted will be called when the
+  // response starts.
+  void Start(std::unique_ptr<storage::BlobDataHandle> blob_data_handle,
+             const net::URLRequestContext* request_context);
+
+  scoped_refptr<net::IOBufferWithSize> response_metadata() {
+    return blob_request_->response_info().metadata;
+  }
+
+  // Same as URLRequestJob::ReadRawData. If ERR_IO_PENDING is returned,
+  // owner_->OnReadRawDataComplete will be called when the read completes.
+  int ReadRawData(net::IOBuffer* buf, int buf_size);
+
+  // net::URLRequest::Delegate overrides
+  void OnReceivedRedirect(net::URLRequest* request,
+                          const net::RedirectInfo& redirect_info,
+                          bool* defer_redirect) override;
+  void OnAuthRequired(net::URLRequest* request,
+                      net::AuthChallengeInfo* auth_info) override;
+  void OnCertificateRequested(
+      net::URLRequest* request,
+      net::SSLCertRequestInfo* cert_request_info) override;
+  void OnSSLCertificateError(net::URLRequest* request,
+                             const net::SSLInfo& ssl_info,
+                             bool fatal) override;
+  void OnResponseStarted(net::URLRequest* request) override;
+  void OnReadCompleted(net::URLRequest* request, int bytes_read) override;
+
+ private:
+  ServiceWorkerURLRequestJob* owner_;
+  std::unique_ptr<net::URLRequest> blob_request_;
+
+  DISALLOW_COPY_AND_ASSIGN(ServiceWorkerBlobReader);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_BLOB_READER_H_