Reland of Improve linearized pdf load/show time.

pdf/url_loader_wrapper.h

Index: pdf/url_loader_wrapper.h
diff --git a/pdf/url_loader_wrapper.h b/pdf/url_loader_wrapper.h
new file mode 100644
index 0000000000000000000000000000000000000000..b95cfd299ff9ce84d2a1e5e1f0bcf5340a9c4ae7
--- /dev/null
+++ b/pdf/url_loader_wrapper.h
@@ -0,0 +1,62 @@
+// 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 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() {}
+
+  // Returns length of content, will be -1, if it is unknown.
+  virtual int GetContentLength() const = 0;
+  // Returns if the response headers contains "accept-ranges".
+  virtual bool IsAcceptRangesBytes() const = 0;
+  // Returns if the content encoded in response.
+  virtual bool IsContentEncoded() const = 0;
+  // Returns response content type.
+  virtual std::string GetContentType() const = 0;
+  // Returns response content disposition.
+  virtual std::string GetContentDisposition() const = 0;
+  // Returns response status code.
+  virtual int GetStatusCode() const = 0;
+  // Returns if the response contains multi parts.
+  virtual bool IsMultipart() const = 0;
+  // If true, [start,end] - is byte range contains in response (include end).
+  // If false, response contains full document, start/end will be undefined.
+  virtual bool GetByteRange(int* start, int* end) const = 0;
+
+  // Close connection.
+  virtual void Close() = 0;
+  // Open new connection and send http range request.
+  virtual void OpenRange(const std::string& url,
+                         const std::string& referrer_url,
+                         uint32_t position,
+                         uint32_t size,
+                         const pp::CompletionCallback& cc) = 0;
+  // Read the response body. The size of the buffer must be large enough to
+  // hold the specified number of bytes to read.
+  // This function might perform a partial read.
+  virtual void ReadResponseBody(char* buffer,
+                                int buffer_size,
+                                const pp::CompletionCallback& cc) = 0;
+  // Returns the current download progress.
+  // Progress only refers to the response body and does not include the headers.
+  // If false, progress is unknown, bytes_received/total_bytes_to_be_received
+  // will be undefined.
+  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_