Don't increment the paint's generation ID when measuring text

All the text measurement methods (measureText, getFontMetrics, breakText)
rely on an internall class called SkAutoRestorePaintTextSizeAndFrame to
save and restore the paint state. This class has the side effect of
always changing the style of the paint once or twice (by forcing the
style to kFill_Style first then by restoring the previous value.)

This is causing Android to incorrectly track paints in hardware display
lists and leading to incorrect renderings. The change simply saves and
restores the generation ID of the paint.

Change-Id: I8f1eea274e8f444e126555bfb937b594170061c0
2 files changed