Abort activation when changing to view mode.

Resolves (Bug 44838)

Changes:
* onLoad: Setup only if activating.  Prevents ve from loading after aborted
while activating.

* onViewTabClick: add clause for activating mode.  Calls deactivate with an
override, and exits activating mode.

Change-Id: Ia61cd1d576b63098419474ad58bc01362c08541e
Merge "Abort activation when changing to view mode."