[MD settings] Removing : (colons) and correcting ClearBrowser data settings

This CL does very minor text touch ups in the settings
UI.  Some lines no longer have ending colons for example
"Font size:" --> "Font size".

BUG=531786,532739

Review URL: https://codereview.chromium.org/1723733003

Cr-Commit-Position: refs/heads/master@{#377117}
1 file changed