gdata: Fix a crash at shutdown with pending gdata operations

chrome/browser/chromeos/extensions/external_filesystem_apitest.cc

Index: chrome/browser/chromeos/extensions/external_filesystem_apitest.cc
diff --git a/chrome/browser/chromeos/extensions/external_filesystem_apitest.cc b/chrome/browser/chromeos/extensions/external_filesystem_apitest.cc
index ef7cdb95ef57630373831e20063e971eb78b663e..10f6d97a1124cafb48d3e6590e42c186847520dd 100644
--- a/chrome/browser/chromeos/extensions/external_filesystem_apitest.cc
+++ b/chrome/browser/chromeos/extensions/external_filesystem_apitest.cc
@@ -299,7 +299,7 @@ IN_PROC_BROWSER_TEST_F(RemoteFileSystemExtensionApiTest,
   // This one is called on exit, but we don't care much about it, as long as it
   // retunrs something valid (i.e. not NULL).
   EXPECT_CALL(*mock_documents_service_, operation_registry()).
-      WillOnce(Return(operation_registry_.get()));
+      WillRepeatedly(Return(operation_registry_.get()));
 
   // All is set... RUN THE TEST.
   EXPECT_TRUE(RunExtensionTest("filesystem_handler")) << message_;