[Hotword] Cleaning up the code.

Clean up includes:
- Update learn more link
- Move learn more link over to the left in the confirm overlay
- Change button to be "cancel" instead of "no thanks"
- Define IsHowtordAllowed to check language & field trial outside of HotwordServiceFactory and replace occurrences of same check elsewhere in code
- Add unittest for IsHotwordAllowed
- Define IsServiceAvailable (have it call IsHotwordingAllowed and check for downloaded extension)

BUG=325439, 289023
R=asargent@chromium.org, jhawkins@chromium.org, samarth@chromium.org

Review URL: https://codereview.chromium.org/152513003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248775 0039d316-1c4b-4281-b951-d872f2087c98
linux-aura: Fix yet more focus issues.

Make sure the FocusIn event is used to activate the widget. The EnterNotify
event does not always activate a window (when XCrossingEvent::focus is not set).
The window receives a FocusIn event in that case, and this should activate the
window.

BUG=336937
R=erg@chromium.org

Review URL: https://codereview.chromium.org/153473003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248776 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248775
SVN changes up to revision 248776