Contain the text color attribute code in HTMLDocument

No one should ever use the vlink/link/text/alink and other color attribute
methods on HTMLBodyElement in C++ code, and the bindings for HTMLBodyElement
are set to Reflect so they never go through these methods anyway. They only
existed to support the code in HTMLDocument.cpp. Instead we can contain all
the logic there and also simplify these methods greatly letting us delete
a bunch of code.

Review URL: https://codereview.chromium.org/26933006

git-svn-id: svn://svn.chromium.org/blink/trunk@159615 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Use DOMURLUtilsReadOnly for Location

Make the readonly attributes use the DOMURLUtilsReadOnly functions.
This does not touch the IDL files at this point but at least we now
share the actual code to stingify these properties.

BUG=303152

Review URL: https://codereview.chromium.org/27056004

git-svn-id: svn://svn.chromium.org/blink/trunk@159616 bbb929c8-8fbe-4397-9dbb-9b2b20218538