Address bar is not "active" when it should be

[Sh1d0w]

• 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).
• Ran git rebase -i to squash commits (if needed).

Makes the url bar active when switching to a about:newtab
page, as the user is expecting to be able to enter his url
when he switches back to a new tab page.

Fixes #3712

Auditors:
@bbondy

Test Plan:
1- Open a new tab
2- Switch to the new blank tab
3- Go back to the tab you were browsing before you opened the new tab
4- Go to the blank new tab you opened in step 1

On step 4, the address bar should be "active", so users could be able to write the web address without need to click on it.

[bbondy]

++ thanks

[srirambv]

This works only if the keyboard shortcuts is used(Ctrl+Tab/Ctrl+Shift+Tab) between tab navigation. If the new tab is selected using mouse the focus is lost again.

[Sh1d0w]

@srirambv Good catch. Will investigate.