Revert 169496 "HTML Imports: Send credentials for same origin re..."

broke maps_pixel_test on gpu debug bots (so far mac and linux, probably win also)

one exampel: http://chromegw.corp.google.com/i/chromium.webkit/builders/GPU%20Mac10.7%20%28dbg%29/builds/23223

> HTML Imports: Send credentials for same origin requests
> 
> This captures following spec chagne: https://www.w3.org/Bugs/Public/show_bug.cgi?id=24905
> The essential part of the change is in HTMLImportsController.cpp.
> Anything else is to make it work with redirect.
> 
> The problem here is that allowCredentials flag is held both
> by ResourceLoaderOptions and ResourceRequest and these two
> can go out-of-sync. This change tries to make them in sync.
> 
> Such a state duplication should be resolved eventually, but
> that is another story.
> 
> BUG=348671
> TEST=import-cors-credentials.html
> R=abarth, dglazkov@chromium.org
> 
> Review URL: https://codereview.chromium.org/196043002

TBR=morrita@chromium.org

Review URL: https://codereview.chromium.org/203593008

git-svn-id: svn://svn.chromium.org/blink/trunk@169504 bbb929c8-8fbe-4397-9dbb-9b2b20218538