Align the gridlines with the preview area.

1. Rename onPreviewAreaSizeChanged() to onPreviewAreaChanged() since it's
passing in the real preview area and is called when the area is changed
regardless of size changes.
2. GridLines.java now draws the lines based on the preview area.

bug:13098715
Change-Id: Idbd2ba03cad4698689cee46d2aa04588a415fa3d
14 files changed