Make sure that begin time cannot be greater than
SMILTime::indefiniteValue unintentionally.

When blink::SVGSMILElement::resolveInterval creates a SMILTime begin
node for a SMILInterval, then it only checks if the value of begin is
indefinite or unresolved but misses the case if it is between these two
reference values.

This patch ensures that no SMILTime can be created above indefiniteValue.

R=dschulze@chromium.org,fs@opera.com
BUG=396044

Review URL: https://codereview.chromium.org/406263002

git-svn-id: svn://svn.chromium.org/blink/trunk@178825 bbb929c8-8fbe-4397-9dbb-9b2b20218538