Make the download's response headers available in the DownloadItem

content/public/test/mock_download_item.h

Index: content/public/test/mock_download_item.h
diff --git a/content/public/test/mock_download_item.h b/content/public/test/mock_download_item.h
index 8ba14fec01cc2a100bbe0f865599c158993fc721..fc7122dbfcb769da70818f2a0f489e9578815d7b 100644
--- a/content/public/test/mock_download_item.h
+++ b/content/public/test/mock_download_item.h
@@ -62,6 +62,8 @@ class MockDownloadItem : public DownloadItem {
   MOCK_CONST_METHOD0(GetTabReferrerUrl, const GURL&());
   MOCK_CONST_METHOD0(GetSuggestedFilename, std::string());
   MOCK_CONST_METHOD0(GetContentDisposition, std::string());
+  MOCK_CONST_METHOD0(GetResponseHeaders,
+                     const scoped_refptr<const net::HttpResponseHeaders>&());
   MOCK_CONST_METHOD0(GetMimeType, std::string());
   MOCK_CONST_METHOD0(GetOriginalMimeType, std::string());
   MOCK_CONST_METHOD0(GetReferrerCharset, std::string());