GTTF: cherry-pick memalign/realloc mismatch debug code

GTTF: cherry-pick memalign/realloc mismatch debug code

Especially ffmpeg may be prone to errors in this area.

Googlers: see b/1397952 for reference.

BUG=30715
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=177171

[jar (doing other things), 2013-01-16 00:59:32]

https://codereview.chromium.org/11823061/diff/1/third_party/tcmalloc/chromium...
File third_party/tcmalloc/chromium/src/debugallocation.cc (right):

https://codereview.chromium.org/11823061/diff/1/third_party/tcmalloc/chromium...
third_party/tcmalloc/chromium/src/debugallocation.cc:754: return mb->offset_ !=
0;
Why is this safe to call if you don't know if this is really a malloc block?

[Paweł Hajdan Jr., 2013-01-16 01:05:09]

https://codereview.chromium.org/11823061/diff/1/third_party/tcmalloc/chromium...
File third_party/tcmalloc/chromium/src/debugallocation.cc (right):

https://codereview.chromium.org/11823061/diff/1/third_party/tcmalloc/chromium...
third_party/tcmalloc/chromium/src/debugallocation.cc:754: return mb->offset_ !=
0;
On 2013/01/16 00:59:32, jar wrote:
> Why is this safe to call if you don't know if this is really a malloc block?

1. Note this has been reviewed and committed Google-side. It's just a backport.
2. See the "Requires that... has been checked for sanity" comment, and we
actually call Check before calling IsMemaligned.

[jar (doing other things), 2013-01-16 01:12:05]

lgtm