Clean up webkit_param_traits.h to use SimilarTypeTraits for enums that don't have custom logic.
Clean up webkit_param_traits.h to use SimilarTypeTraits for enums that don't
have custom logic.

BUG=None
TEST=Compiles
Review URL: http://codereview.chromium.org/3333008

git-svn-id: http://src.chromium.org/svn/trunk/src@58368 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 2737a8de16d8f419da3145f3a24ce515cd7374ce
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser