Simplify / fix SkBitmap::ReadRawPixels()

We no longer need to look at the field snugRB except to check for the
simple no-pixels case.  This is good, because our snugRB <= ramRB check
is actually too weak, and is the source of this linked Chromium issue.

BUG=chromium:765858

Instead of doing complicated checks against that stored snugRB and the
computed ramRB, we now just ignore snugRB.  We know the images written
by write_row_bytes() will be snug, so we can just look at width, height,
and color type to figure out exactly how many bytes we should be
reading.

Then it becomes the call to readByteArray()'s responsibility to make
sure that we have an array there of exactly that many bytes to read.
We've just got to make sure we check for its failure.

Change-Id: Ia05c36d8a77b0de16ee03a80f6cb2dab6fcedbae
Reviewed-on: https://skia-review.googlesource.com/50800
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
1 file changed