Origin spoofing possible due to inappropriate URL escape sequence decoding

https://bugs.webkit.org/show_bug.cgi?id=131837
rdar://problem/15211936

Reviewed by Anders Carlsson and Dave Hyatt.

Tests: fast/dom/DOMURL/parsing.html
       fast/dom/HTMLAnchorElement/anchor-element-href-parsing.html

* platform/URL.cpp:
(WebCore::URL::host): Removed unnecessary call to
decodeURLEscapeSequences, which caused
problems and was not needed.

Change-Id: Idddc6efe310389b8e68db2d8c312c2098121e6d9
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@167480 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Reviewed-by: Michael Bruning <michael.bruning@digia.com>