Move ElementResolveContext out of StyleResolverState.h/cpp

Move ElementResolveContext class out of StyleResolverState.h/cpp and
into ElementResolveContext.h/cpp respectively.
This breaks the ElementRuleCollector dependency on StyleResolverState.

BUG=237268
R=dglazkov@chromium.org

Review URL: https://chromiumcodereview.appspot.com/20433002

git-svn-id: svn://svn.chromium.org/blink/trunk@155014 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mark fast/js/kde/inbuilt_function_tostring.html temporarily as flaky

The output changes slightly when we switch v8's i18n support on. After
that has happened, this test needs to be rebaselined.

BUG=v8:2745
TBR=danno@chromium.org

Review URL: https://codereview.chromium.org/20818003

git-svn-id: svn://svn.chromium.org/blink/trunk@155015 bbb929c8-8fbe-4397-9dbb-9b2b20218538