Hide the load time from URL bar on all platforms if below the narrow breakpoint

[bsclifton]

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests). N/A
• Ran git rebase -i to squash commits (if needed).

Hide the load time from URL bar on all platforms if below the narrow breakpoint (600px)

Fixes #1046

Auditors: @bradleyrichter

Test Plan:

1. Make sure browser width is greater than 600px
2. Open http://example.com and ensure the load timer shows up in the URL bar
3. Resize the window until it's less than 600px
4. Confirm load timer no longer shows

[bbondy]

nice, thanks.