Update Linux to use scoped_refptr<T>::get() rather than implicit "operator T*"

webkit/browser/fileapi/async_file_test_helper.cc

Index: webkit/browser/fileapi/async_file_test_helper.cc
diff --git a/webkit/browser/fileapi/async_file_test_helper.cc b/webkit/browser/fileapi/async_file_test_helper.cc
index d60a68eb0fe1bc42082cf0a7866a9bd7b80f6618..476fdcd168becfec85c5f93eadfe49667c087ecb 100644
--- a/webkit/browser/fileapi/async_file_test_helper.cc
+++ b/webkit/browser/fileapi/async_file_test_helper.cc
@@ -51,7 +51,7 @@ void CreateSnapshotFileCallback(
     const base::PlatformFileInfo& file_info,
     const base::FilePath& platform_path,
     const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref) {
-  DCHECK(!file_ref);
+  DCHECK(!file_ref.get());
   *result_out = result;
   if (platform_path_out)
     *platform_path_out = platform_path;