Prevent URLFetcher::AppendChunkedData from dereferencing NULL pointers.

net/url_request/url_request.cc

Index: net/url_request/url_request.cc
diff --git a/net/url_request/url_request.cc b/net/url_request/url_request.cc
index 9fa81a760b0be307ef703d024f2d5270e16b08d0..b8f21bf249cb958191fbc0a18b05422dfb7cb19d 100644
--- a/net/url_request/url_request.cc
+++ b/net/url_request/url_request.cc
@@ -21,7 +21,6 @@
 #include "base/synchronization/lock.h"
 #include "base/values.h"
 #include "net/base/auth.h"
-#include "net/base/chunked_upload_data_stream.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/load_flags.h"
 #include "net/base/load_timing_info.h"
@@ -191,22 +190,6 @@ URLRequest::~URLRequest() {
   net_log_.EndEventWithNetErrorCode(NetLog::TYPE_REQUEST_ALIVE, net_error);
 }
 
-void URLRequest::EnableChunkedUpload() {
-  DCHECK(!upload_data_stream_ || upload_data_stream_->is_chunked());
-  if (!upload_data_stream_) {
-    upload_chunked_data_stream_ = new ChunkedUploadDataStream(0);
-    upload_data_stream_.reset(upload_chunked_data_stream_);
-  }
-}
-
-void URLRequest::AppendChunkToUpload(const char* bytes,
-                                     int bytes_len,
-                                     bool is_last_chunk) {
-  DCHECK(upload_data_stream_);
-  DCHECK(upload_data_stream_->is_chunked());
-  upload_chunked_data_stream_->AppendData(bytes, bytes_len, is_last_chunk);
-}
-
 void URLRequest::set_upload(scoped_ptr<UploadDataStream> upload) {
   upload_data_stream_ = std::move(upload);
 }