Add encoded_data_length argument to didDownloadData delegate method

public/platform/WebURLLoaderClient.h

Index: public/platform/WebURLLoaderClient.h
diff --git a/public/platform/WebURLLoaderClient.h b/public/platform/WebURLLoaderClient.h
index 3313a9c03947d897d36b914539145d58f270591e..1826b484320f54039310c1cdde6866a6e60e09ef 100644
--- a/public/platform/WebURLLoaderClient.h
+++ b/public/platform/WebURLLoaderClient.h
@@ -55,7 +55,10 @@ public:
 
     // 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(WebURLLoader*, int dataLength) { }
+    virtual void didDownloadData(WebURLLoader*, int dataLength, int encodedDataLength) { }
+    // FIXME: Remove this stub function when Chrome-side change propagating the
+    // encodedDataLength is landed.
+    virtual void didDownloadData(WebURLLoader* loader, int dataLength) { didDownloadData(loader, dataLength, -1); }
 
     // Called when a chunk of response data is received.
     virtual void didReceiveData(WebURLLoader*, const char* data, int dataLength, int encodedDataLength) { }