Update from https://crrev.com/303153

net/http/http_stream_base.h

-// Copyright (c) 2012 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.
-//
-// HttpStreamBase is an interface for reading and writing data to an
-// HTTP-like stream that keeps the client agnostic of the actual underlying
-// transport layer.  This provides an abstraction for HttpStream and
-// WebSocketHandshakeStreamBase.
-
-#ifndef NET_HTTP_HTTP_STREAM_BASE_H_
-#define NET_HTTP_HTTP_STREAM_BASE_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/memory/scoped_ptr.h"
-#include "net/base/completion_callback.h"
-#include "net/base/net_export.h"
-#include "net/base/request_priority.h"
-#include "net/base/upload_progress.h"
-
-namespace net {
-
-class BoundNetLog;
-class HttpNetworkSession;
-class HttpRequestHeaders;
-struct HttpRequestInfo;
-class HttpResponseInfo;
-class IOBuffer;
-struct LoadTimingInfo;
-class SSLCertRequestInfo;
-class SSLInfo;
-
-class NET_EXPORT_PRIVATE HttpStreamBase {
- public:
-  HttpStreamBase() {}
-  virtual ~HttpStreamBase() {}
-
-  // Initialize stream.  Must be called before calling SendRequest().
-  // |request_info| must outlive the HttpStreamBase.
-  // Returns a net error code, possibly ERR_IO_PENDING.
-  virtual int InitializeStream(const HttpRequestInfo* request_info,
-                               RequestPriority priority,
-                               const BoundNetLog& net_log,
-                               const CompletionCallback& callback) = 0;
-
-  // Writes the headers and uploads body data to the underlying socket.
-  // ERR_IO_PENDING is returned if the operation could not be completed
-  // synchronously, in which case the result will be passed to the callback
-  // when available. Returns OK on success.
-  //
-  // The callback will only be invoked once the first full set of headers have
-  // been received, at which point |response| will have been populated with that
-  // set of headers, and is safe to read, until/unless ReadResponseHeaders is
-  // called.
-  //
-  // |response| must remain valid until all sets of headers has been read, or
-  // the HttpStreamBase is destroyed. There's typically only one set of
-  // headers, except in the case of 1xx responses (See ReadResponseHeaders).
-  virtual int SendRequest(const HttpRequestHeaders& request_headers,
-                          HttpResponseInfo* response,
-                          const CompletionCallback& callback) = 0;
-
-  // Reads from the underlying socket until the next set of response headers
-  // have been completely received.  This may only be called on 1xx responses
-  // after SendRequest has completed successfully, to read the next set of
-  // headers.
-  //
-  // ERR_IO_PENDING is returned if the operation could not be completed
-  // synchronously, in which case the result will be passed to the callback when
-  // available. Returns OK on success. The response headers are available in
-  // the HttpResponseInfo passed in to original call to SendRequest.
-  virtual int ReadResponseHeaders(const CompletionCallback& callback) = 0;
-
-  // Reads response body data, up to |buf_len| bytes. |buf_len| should be a
-  // reasonable size (<2MB). The number of bytes read is returned, or an
-  // error is returned upon failure.  0 indicates that the request has been
-  // fully satisfied and there is no more data to read.
-  // ERR_CONNECTION_CLOSED is returned when the connection has been closed
-  // prematurely.  ERR_IO_PENDING is returned if the operation could not be
-  // completed synchronously, in which case the result will be passed to the
-  // callback when available. If the operation is not completed immediately,
-  // the socket acquires a reference to the provided buffer until the callback
-  // is invoked or the socket is destroyed.
-  virtual int ReadResponseBody(IOBuffer* buf, int buf_len,
-                               const CompletionCallback& callback) = 0;
-
-  // Closes the stream.
-  // |not_reusable| indicates if the stream can be used for further requests.
-  // In the case of HTTP, where we re-use the byte-stream (e.g. the connection)
-  // this means we need to close the connection; in the case of SPDY, where the
-  // underlying stream is never reused, it has no effect.
-  // TODO(mbelshe): We should figure out how to fold the not_reusable flag
-  //                into the stream implementation itself so that the caller
-  //                does not need to pass it at all.  We might also be able to
-  //                eliminate the SetConnectionReused() below.
-  virtual void Close(bool not_reusable) = 0;
-
-  // Indicates if the response body has been completely read.
-  virtual bool IsResponseBodyComplete() const = 0;
-
-  // Indicates that the end of the response is detectable. This means that
-  // the response headers indicate either chunked encoding or content length.
-  // If neither is sent, the server must close the connection for us to detect
-  // the end of the response.
-  // TODO(rch): Rename this method, so that it is clear why it exists
-  // particularly as it applies to QUIC and SPDY for which the end of the
-  // response is always findable.
-  virtual bool CanFindEndOfResponse() const = 0;
-
-  // A stream exists on top of a connection.  If the connection has been used
-  // to successfully exchange data in the past, error handling for the
-  // stream is done differently.  This method returns true if the underlying
-  // connection is reused or has been connected and idle for some time.
-  virtual bool IsConnectionReused() const = 0;
-  virtual void SetConnectionReused() = 0;
-
-  // Checks whether the current state of the underlying connection
-  // allows it to be reused.
-  virtual bool IsConnectionReusable() const = 0;
-
-  // Get the total number of bytes received from network for this stream.
-  virtual int64 GetTotalReceivedBytes() const = 0;
-
-  // Populates the connection establishment part of |load_timing_info|, and
-  // socket ID.  |load_timing_info| must have all null times when called.
-  // Returns false and does nothing if there is no underlying connection, either
-  // because one has yet to be assigned to the stream, or because the underlying
-  // socket has been closed.
-  //
-  // In practice, this means that this function will always succeed any time
-  // between when the full headers have been received and the stream has been
-  // closed.
-  virtual bool GetLoadTimingInfo(LoadTimingInfo* load_timing_info) const = 0;
-
-  // Get the SSLInfo associated with this stream's connection.  This should
-  // only be called for streams over SSL sockets, otherwise the behavior is
-  // undefined.
-  virtual void GetSSLInfo(SSLInfo* ssl_info) = 0;
-
-  // Get the SSLCertRequestInfo associated with this stream's connection.
-  // This should only be called for streams over SSL sockets, otherwise the
-  // behavior is undefined.
-  virtual void GetSSLCertRequestInfo(SSLCertRequestInfo* cert_request_info) = 0;
-
-  // HACK(willchan): Really, we should move the HttpResponseDrainer logic into
-  // the HttpStream implementation. This is just a quick hack.
-  virtual bool IsSpdyHttpStream() const = 0;
-
-  // In the case of an HTTP error or redirect, flush the response body (usually
-  // a simple error or "this page has moved") so that we can re-use the
-  // underlying connection. This stream is responsible for deleting itself when
-  // draining is complete.
-  virtual void Drain(HttpNetworkSession* session) = 0;
-
-  // Called when the priority of the parent transaction changes.
-  virtual void SetPriority(RequestPriority priority) = 0;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(HttpStreamBase);
-};
-
-}  // namespace net
-
-#endif  // NET_HTTP_HTTP_STREAM_BASE_H_