Add a setTimer() function.

Seemed simple, but required adding a Global class that contains all the global state (instance and context) for our running V8 instance. Also moved canvas.inval to be just inval() at the global level.

BUG=
R=robertphillips@google.com

Author: jcgregorio@google.com

Review URL: https://codereview.chromium.org/103143009

git-svn-id: http://skia.googlecode.com/svn/trunk@12730 2bbb7eff-a529-9590-31e7-b0007b416f81
6 files changed