Revert 57094 - Making window.focus()/blur() work only when there is a user ge...

Revert 57094 - Making window.focus()/blur() work only when there is a user gesture.

Also making window.focus() select tab if it is not visible.
The RenderViewHost now calls ActivateContent and the new DeactivateContent (instead of using the recently added TabContentsDelegate::Activate/Deactivate methods which have been removed).

BUG=29643, 52346
TEST=Create a page with buttons that call window.focus()/blur() directly and with a timeout. When called directly, the calls should succeed (the browser should be activated/deactivated). When called with a timeout, nothing should happen. Also test that a popup calling window.opener.focus() cause the opening tab to become selected when it is not the current tab.

Review URL: http://codereview.chromium.org/3156016

TBR=jcivelli@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=57105