Revert of isActiveFocus() is a more meaningful name (https://codereview.chromium.org/260353003/)

Reason for revert:
Clearly there's opposition to this naming, best to revert while we discuss.

Original issue's description:
> isActiveFocus() is a more meaningful name
> 
> Previously the function was named isActive() which
> didn't lay emphasis on the behavior and purpose of
> the function. There was a FIXME to rename the
> function to isActiveFocus().
> 
> Patch for doing the same.
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=172911

TBR=jochen@chromium.org,jamesr@chromium.org,pdr@chromium.org,abarth@chromium.org,eseidel@chromium.org,suyash.s@samsung.com
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/269433002

git-svn-id: svn://svn.chromium.org/blink/trunk@172991 bbb929c8-8fbe-4397-9dbb-9b2b20218538