Revert of HTML Imports: Send credentials for same origin requests (https://codereview.chromium.org/196043002/)

Reason for revert:
The following tests crash on all debug bots.
- fast/shapes/shape-inside/shape-inside-image-set.html
- fast/shapes/shape-outside-floats/shape-outside-image-set.html


Original issue's description:
> 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=dglazkov@chromium.org, japhet@chromium.org, abarth
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169496
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169578

TBR=abarth@chromium.org,dglazkov@chromium.org,japhet@chromium.org,morrita@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=348671

Review URL: https://codereview.chromium.org/199733008

git-svn-id: svn://svn.chromium.org/blink/trunk@169618 bbb929c8-8fbe-4397-9dbb-9b2b20218538