[Android WebView] Fixed width set in the viewport tag must not be scaled by target-densitydpi

Legacy WebView only scales the layout width if it is set to 'device-width' or 'auto',
but not if it is set explicitly as a numeric value.

BUG=302974

Review URL: https://codereview.chromium.org/25356004

git-svn-id: svn://svn.chromium.org/blink/trunk@158920 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Break core/platform/network dependency on CSP

This CL just moves an enum from ContentSecurityPolicy into HTTPParsers.h

R=jochen@chromium.org
BUG=297477

Review URL: https://codereview.chromium.org/25983002

git-svn-id: svn://svn.chromium.org/blink/trunk@158921 bbb929c8-8fbe-4397-9dbb-9b2b20218538