Webkit/Source/web/WebLocalFrameImpl microcleanup

Cleanup, no new code:
- early return in the method
- removed {} for one-line bodies, following the
style of the method.

(stumbled upon this in http://crrev.com/1794553002)

Review URL: https://codereview.chromium.org/1811753004

Cr-Commit-Position: refs/heads/master@{#382014}
1 file changed