Preserve custom headers when following cross-origin redirects.

third_party/WebKit/Source/core/loader/DocumentThreadableLoader.h

Index: third_party/WebKit/Source/core/loader/DocumentThreadableLoader.h
diff --git a/third_party/WebKit/Source/core/loader/DocumentThreadableLoader.h b/third_party/WebKit/Source/core/loader/DocumentThreadableLoader.h
index 9c65950d96f9ee5c920eafc8b03466d3e6312a7f..8f5cbf49c9fd2402500cd39cd3d05395efddb90e 100644
--- a/third_party/WebKit/Source/core/loader/DocumentThreadableLoader.h
+++ b/third_party/WebKit/Source/core/loader/DocumentThreadableLoader.h
@@ -217,8 +217,8 @@ class CORE_EXPORT DocumentThreadableLoader final : public ThreadableLoader,
   ResourceRequest m_actualRequest;
   ResourceLoaderOptions m_actualOptions;
 
-  // stores simple request headers in case of a cross-origin redirect.
-  HTTPHeaderMap m_simpleRequestHeaders;
+  // stores request headers in case of a cross-origin redirect.
+  HTTPHeaderMap m_requestHeaders;

[yhirano, 2016/11/07 07:48:30]

Do we still need this? Is it enough to use the headers on the original request?

[tyoshino (SeeGerritForStatus), 2016/11/07 10:48:17]

Yeah, it's good to try it to see if just depending on |request| argument of
redirectReceived() works. But don't we need to recover the 3 headers cleared in
redirectReceived() anyway? Or, just also removing all the clearHTTP.*() calls
would be fine?

[yhirano, 2016/11/07 12:30:50]

Ah, you're right, thank you.

[Jack Bates, 2016/11/12 21:13:30]

Do you have any tips on how to inspect the HTTPHeaderMap object?

[yhirano, 2016/11/14 08:42:43]

I don't know. You can print hashmap entries like


request.m_httpHeaderFields.m_headers.m_impl.m_table[2].key.m_string.utf8(WTF::LenientUTF8Conversion).data()

, but it's not that user-friendly.

 
   Timer<DocumentThreadableLoader> m_timeoutTimer;
   double