Minor fixes for SampleApp.

- Add a comment for invalidating in onSizeChange.
- Call base constructor for SkOSWindow_Unix.
- Call onSizeChange in SampleWindow constructor so fZoomCenter gets set.


git-svn-id: http://skia.googlecode.com/svn/trunk@1627 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed