Support for larger than "signed 32b limit" sized bitmaps in BGRAConvolve2D.

Support for larger than "signed 32b limit" sized bitmaps in BGRAConvolve2D.

The multiplication of 2 signed ints was producing a result larger than what's supported by a single signed int and the memory was accessed out of bounds. Using uint64_t solves the issue.

BUG=378491
Committed: https://skia.googlesource.com/skia/+/35fcd15d0598bca6a265100ace5d10a0d992cf9c

[reed1, 2014-06-10 21:33:39]

lgtm

Lets create some tests (after this CL) that stress this more, so we can find
other places where we need to be more guarded.

[sugoi1, 2014-06-11 12:01:05]

The CQ bit was checked by sugoi@chromium.org

[sugoi1, 2014-06-11 12:01:09]

The CQ bit was unchecked by sugoi@chromium.org

[sugoi1, 2014-06-11 12:27:57]

The CQ bit was checked by sugoi@chromium.org

[commit-bot: I haz the power, 2014-06-11 12:28:37]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/sugoi@chromium.org/323013005/1

[reed1, 2014-06-11 12:32:03]

I like the change, but lets *definitely* write a unittest that crashes on the
old code, so we can be sure not to regress.

[rmistry, 2014-06-11 13:16:43]

The CQ bit was unchecked by rmistry@google.com

[rmistry, 2014-06-11 13:17:21]

I had restarted Skia's CQ which changed some trybots, it appears this CL was
stuck in between states, I will try triggering it again.

[rmistry, 2014-06-11 13:17:27]

The CQ bit was checked by rmistry@google.com

[commit-bot: I haz the power, 2014-06-11 13:17:58]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/sugoi@chromium.org/323013005/1

[commit-bot: I haz the power, 2014-06-11 13:31:32]

Change committed as 35fcd15d0598bca6a265100ace5d10a0d992cf9c