andreasgal/j2me.js — pull request #721 by yxl (2014-12-12 10:09:52+00:00)
Title: Don't reassign the canvas context font if there is no change.

I found in a midlet that the same font could be set to the context multiple times.
Since setting the font of the canvas context is an expensive operation, I removed these unnecessary font setting operations and reduced 3/4 of total calling time with the `Font.stringWidth` method.