Add request header on gdata operation for testing ETag match.

chrome/browser/google_apis/gdata_wapi_service_browsertest.cc

Index: chrome/browser/google_apis/gdata_wapi_service_browsertest.cc
diff --git a/chrome/browser/google_apis/gdata_wapi_service_browsertest.cc b/chrome/browser/google_apis/gdata_wapi_service_browsertest.cc
index decb58e6002f0776c740111502b6ace63fcbfd35..79d1a7cdb40905825d0c320ba983394b6df15c3f 100644
--- a/chrome/browser/google_apis/gdata_wapi_service_browsertest.cc
+++ b/chrome/browser/google_apis/gdata_wapi_service_browsertest.cc
@@ -82,6 +82,7 @@ IN_PROC_BROWSER_TEST_F(GDataTest, Download) {
       GetTestCachedFilePath(FilePath(
           FILE_PATH_LITERAL("cached_testfile.txt"))),
       gdata_test_server_.GetURL("files/chromeos/gdata/testfile.txt"),
+      std::string(),  // ETag
       base::Bind(&TestDownloadCallback, &result, &contents),
       gdata::GetContentCallback());
   content::RunMessageLoop();
@@ -102,6 +103,7 @@ IN_PROC_BROWSER_TEST_F(GDataTest, NonExistingDownload) {
       GetTestCachedFilePath(FilePath(
           FILE_PATH_LITERAL("cache_no-such-file.txt"))),
       gdata_test_server_.GetURL("files/chromeos/gdata/no-such-file.txt"),
+      std::string(),  // ETag
       base::Bind(&TestDownloadCallback, &result, &dummy_contents),
       gdata::GetContentCallback());
   content::RunMessageLoop();