Fix implicit ptr to bool

Bug: skia:
Change-Id: I11ce7858306dfe05162aa84a5f862b1b01c2cee9
Reviewed-on: https://skia-review.googlesource.com/15637
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>
1 file changed