Merge 159454 - Flush at the end of local file writing in FileWriter API.

net/base/mock_file_stream.cc

Index: net/base/mock_file_stream.cc
===================================================================
--- net/base/mock_file_stream.cc	(revision 160294)
+++ net/base/mock_file_stream.cc	(working copy)
@@ -54,10 +54,14 @@
   return ReturnError64(FileStream::Truncate(bytes));
 }
 
-int MockFileStream::Flush() {
-  return ReturnError(FileStream::Flush());
+int MockFileStream::Flush(const CompletionCallback& callback) {
+  return ReturnError(FileStream::Flush(callback));
 }
 
+int MockFileStream::FlushSync() {
+  return ReturnError(FileStream::FlushSync());
+}
+
 }  // namespace testing
 
 }  // namespace net