Add ProgressCallback to DriveServiceInterface::DownloadFile.

chrome/browser/google_apis/test_util.h

Index: chrome/browser/google_apis/test_util.h
diff --git a/chrome/browser/google_apis/test_util.h b/chrome/browser/google_apis/test_util.h
index 40230fa3a82aac7f79a383d2422496853e193bf9..e230894c90d3336f80cc2846a1e7e492e0990621 100644
--- a/chrome/browser/google_apis/test_util.h
+++ b/chrome/browser/google_apis/test_util.h
@@ -6,6 +6,8 @@
 #define CHROME_BROWSER_GOOGLE_APIS_TEST_UTIL_H_
 
 #include <string>
+#include <utility>
+#include <vector>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ -265,6 +267,13 @@ CreateCopyResultCallback(T1* out1, T2* out2, T3* out3, T4* out4) {
       internal::OutputParams<T1, T2, T3, T4>(out1, out2, out3, out4));
 }
 
+typedef std::pair<int64, int64> ProgressInfo;
+
+// Helper utility for recording the results via ProgressCallback.
+void AppendProgressCallbackResult(std::vector<ProgressInfo>* progress_values,
+                                  int64 progress,
+                                  int64 total);
+
 }  // namespace test_util
 }  // namespace google_apis