Rename some methods by removing 'AfterLayout' postfix

We'll need these methods to invalidate paints even there is no layout.

This change is remaning only, without any change of functionality.

BUG=394004
R=dsinclair@chromium.org
TBR=leviw@chromium.org

Review URL: https://codereview.chromium.org/396803005

git-svn-id: svn://svn.chromium.org/blink/trunk@178300 bbb929c8-8fbe-4397-9dbb-9b2b20218538