Dispatch encoded_data_length separately in content/child

third_party/WebKit/public/platform/WebURLLoaderClient.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 61 matching lines @@
 
   // Called when a chunk of response data is downloaded. This is only called
   // if WebURLRequest's downloadToFile flag was set to true.
   virtual void didDownloadData(int dataLength, int encodedDataLength) {}
 
   // Called when a chunk of response data is received. |dataLength| is the
   // number of bytes pointed to by |data|. |encodedDataLength| is the number
   // of bytes actually received from network to serve this chunk, including
   // HTTP headers and framing if relevant. It is 0 if the response was served
   // from cache, and -1 if this information is unavailable.
-  // TODO(ricea): -1 is problematic for consumers maintaining a running
-  //     total. Investigate using 0 for all unavailable cases.
-  virtual void didReceiveData(const char* data,
-                              int dataLength,
-                              int encodedDataLength) {}
+  virtual void didReceiveData(const char* data, int dataLength) {}
+
+  // Called when the number of bytes actually received from network including
+  // HTTP headers is updated. |transferSizeDiff| is positive.

[kinuko, 2016/12/07 04:06:26]

Should transferSizeDiff be unsigned if it's always positive?

[yhirano, 2016/12/07 12:06:58]

ditto

+  virtual void didReceiveTransferSizeUpdate(int transferSizeDiff) {}
 
   // Called when a chunk of renderer-generated metadata is received from the
   // cache.
   virtual void didReceiveCachedMetadata(const char* data, int dataLength) {}
 
   // Called when the load completes successfully.
   // |totalEncodedDataLength| may be equal to kUnknownEncodedDataLength.
   virtual void didFinishLoading(double finishTime,
                                 int64_t totalEncodedDataLength,
                                 int64_t totalEncodedBodyLength) {}
 
   // Called when the load completes with an error.
   // |totalEncodedDataLength| may be equal to kUnknownEncodedDataLength.
   virtual void didFail(const WebURLError&,
                        int64_t totalEncodedDataLength,
                        int64_t totalEncodedBodyLength) {}
 
   // Value passed to didFinishLoading when total encoded data length isn't
   // known.
   static const int64_t kUnknownEncodedDataLength = -1;
 
  protected:
   virtual ~WebURLLoaderClient() {}
 };
 
 }  // namespace blink
 
 #endif