Disable ResponseResponse lazy initialization for WebKit2 as we always end up initializing all the fields anyway when sending the response to the WebContent process via IPC. Even worse, we always do a partial lazy initialization (common fields only) before the IPC so we always do the initialization in 2 steps. This normally would not be an issue but the 2 steps actually have some overlap because both call CFHTTPMessageCopyAllHeaderFields(), which is expensive (See <rdar://problem/26796059>) to first get the common HTTP headers, then ALL the HTTP headers.
<rdar://problem/27209066>
Created attachment 282963 [details] Patch
Comment on attachment 282963 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=282963&action=review > Source/WebCore/ChangeLog:3 > + [WK2][Cocoa] Disable ResponseResponse lazy initialization ResourceResponse.
Committed r202888: <http://trac.webkit.org/changeset/202888>