Initialize rects in SkValidatingReadBuffer readRect & readIRect on failure

BUG: 726199

Change-Id: I2afeebbd2240e1c2f3b7d7298cb11572eef18acd
Reviewed-on: https://skia-review.googlesource.com/17984
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Mike Reed <reed@google.com>
1 file changed