Prevent URLFetcher::AppendChunkedData from dereferencing NULL pointers.

components/cronet/android/url_request_adapter.h

Index: components/cronet/android/url_request_adapter.h
diff --git a/components/cronet/android/url_request_adapter.h b/components/cronet/android/url_request_adapter.h
index d632b911229da0ff565deb524a96ba4202bd3c4c..8c4e03371e2734f28e3986f01b10267a820911fd 100644
--- a/components/cronet/android/url_request_adapter.h
+++ b/components/cronet/android/url_request_adapter.h
@@ -13,13 +13,14 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "net/base/chunked_upload_data_stream.h"
 #include "net/base/request_priority.h"
 #include "net/http/http_request_headers.h"
 #include "net/url_request/url_request.h"
 
 namespace net {
-class IOBufferWithSize;
 class HttpResponseHeaders;
+class IOBufferWithSize;
 class UploadDataStream;
 struct RedirectInfo;
 }  // namespace net
@@ -156,6 +157,7 @@ class URLRequestAdapter : public net::URLRequest::Delegate {
   net::HttpRequestHeaders headers_;
   scoped_ptr<net::URLRequest> url_request_;
   scoped_ptr<net::UploadDataStream> upload_data_stream_;
+  scoped_ptr<net::ChunkedUploadDataStream::Writer> chunked_upload_writer_;
   scoped_refptr<net::IOBufferWithSize> read_buffer_;
   int total_bytes_read_;
   int error_code_;