Improve linearized pdf load/show time.

pdf/url_loader_wrapper.h

+// Copyright (c) 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 PDF_URL_LOADER_WRAPPER_H_
+#define PDF_URL_LOADER_WRAPPER_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "ppapi/cpp/completion_callback.h"
+
+namespace chrome_pdf {
+
+class URLLoaderWrapper {
+ public:
+  virtual ~URLLoaderWrapper() {}

[Lei Zhang, 2016/10/21 09:33:10]

nit: blank line after.

[snake, 2016/10/21 15:13:16]

Done.

+  virtual int GetContentLength() const = 0;

[Lei Zhang, 2016/10/21 09:33:10]

Please document virtual methods. e.g. Does this return negative values on error?

[snake, 2016/10/21 15:13:16]

Done.

+  virtual bool IsAcceptRangesBytes() const = 0;
+  virtual bool IsContentEncoded() const = 0;
+  virtual std::string GetContentType() const = 0;
+  virtual std::string GetContentDisposition() const = 0;
+  virtual int GetStatusCode() const = 0;
+  virtual bool IsMultipart() const = 0;
+  virtual bool GetByteRange(int* start, int* end) const = 0;

[Lei Zhang, 2016/10/21 09:33:10]

If this returns false, does |start| and |end| get some predetermined values, or
are do they remain potentially uninitialized?

Is it [start, end] or [start, end) ?

[snake, 2016/10/21 15:13:16]

Done.

+
+  virtual void Close() = 0;
+  virtual void OpenRange(const std::string& url,
+                         const std::string& referrer_url,
+                         uint32_t position,
+                         uint32_t size,
+                         const pp::CompletionCallback& cc) = 0;
+
+  virtual void ReadResponseBody(char* buffer,
+                                int buffer_size,
+                                const pp::CompletionCallback& cc) = 0;
+  virtual bool GetDownloadProgress(
+      int64_t* bytes_received,
+      int64_t* total_bytes_to_be_received) const = 0;
+};
+
+}  // namespace chrome_pdf
+
+#endif  // PDF_URL_LOADER_WRAPPER_H_