webtry: Do not forget the close the rows.

This should prevent further enumeration according to the docs.

http://golang.org/pkg/database/sql/#Rows.Close

BUG=None
TEST=None
R=humper@google.com

Review URL: https://codereview.chromium.org/638373003
Change drawText() to generate positions and send to drawPosText()

The idea here is to have a central place that does layout for drawText(), and
then always feed text through drawPosText(). This both makes all of the
GrTextContexts consistent in drawText() output, and does a better job of
stressing drawPosText().

Because of the effect of matrices on hinting and approximation error, the
generated text is not 100% identical to that produced by the raster pipeline.

BUG=skia:2778

Review URL: https://codereview.chromium.org/653133004