Introduce UI for changing benchmark configuration
Introduce UI for changing benchmark configuration

Also merges parameter and config

R=ricea@chromium.org

Review URL: https://codereview.appspot.com/123790044
google/pywebsocket,googlearchive/pywebsocket,google/pywebsocket,googlearchive/pywebsocket,GoogleChromeLabs/pywebsocket3,GoogleChromeLabs/pywebsocket3,GoogleChromeLabs/pywebsocket3,googlearchive/pywebsocket,google/pywebsocket