net: FileStream::Read/Write() to take IOBuffer* instead of char*

webkit/blob/blob_url_request_job.h

Index: webkit/blob/blob_url_request_job.h
diff --git a/webkit/blob/blob_url_request_job.h b/webkit/blob/blob_url_request_job.h
index 6652ca3d58727b4da17434a1b5468364e7f0290b..c069a6c7c3a57c1b59755b8658fe67d64f7f93b0 100644
--- a/webkit/blob/blob_url_request_job.h
+++ b/webkit/blob/blob_url_request_job.h
@@ -19,7 +19,9 @@ struct PlatformFileInfo;
 }
 
 namespace net {
+class DrainableIOBuffer;
 class FileStream;
+class IOBuffer;
 }
 
 namespace webkit_blob {
@@ -79,10 +81,7 @@ class BLOB_EXPORT BlobURLRequestJob : public net::URLRequestJob {
   int64 total_size_;
   int64 current_item_offset_;
   int64 remaining_bytes_;
-  scoped_refptr<net::IOBuffer> read_buf_;
-  int read_buf_offset_;
-  int read_buf_size_;
-  int read_buf_remaining_bytes_;
+  scoped_refptr<net::DrainableIOBuffer> read_buf_;
   int bytes_to_read_;
   bool error_;
   bool headers_set_;