iSAC float: Handle errors in upper band decoding

iSAC float: Handle errors in upper band decoding

We hit a fuzzer bug that caused numDecodedBytesLB + numDecodedBytesUB
> lenEncodedBytes, which is obviously bogus. Check for that, and for
the case whhere the UB decoder itself realized that something was
wrong. (The code already makes the corresponding check for the LB
decoder.)

BUG=chromium:637899
(cherry picked from commit d52bef7d6445070532b3c8463859ee4e1f99d70f)

Committed: https://chromium.googlesource.com/external/webrtc/+/1605d3a146e894e16975dffaa7c60f7658f2ce97

[kwiberg-webrtc, 2016-09-07 08:15:49]

Description was changed from

==========
iSAC float: Handle errors in upper band decoding

We hit a fuzzer bug that caused numDecodedBytesLB + numDecodedBytesUB
> lenEncodedBytes, which is obviously bogus. Check for that, and for
the case whhere the UB decoder itself realized that something was
wrong. (The code already makes the corresponding check for the LB
decoder.)

BUG=chromium:637899

(cherry picked from commit d52bef7d6445070532b3c8463859ee4e1f99d70f)
==========

to

==========
iSAC float: Handle errors in upper band decoding

We hit a fuzzer bug that caused numDecodedBytesLB + numDecodedBytesUB
> lenEncodedBytes, which is obviously bogus. Check for that, and for
the case whhere the UB decoder itself realized that something was
wrong. (The code already makes the corresponding check for the LB
decoder.)

BUG=chromium:637899

(cherry picked from commit d52bef7d6445070532b3c8463859ee4e1f99d70f)

Committed:
https://chromium.googlesource.com/external/webrtc/+/1605d3a146e894e16975dffaa...
==========

[kwiberg-webrtc, 2016-09-07 08:15:51]

Committed patchset #1 (id:1) manually as
1605d3a146e894e16975dffaa7c60f7658f2ce97.

[kwiberg-webrtc, 2016-09-07 08:21:37]

kwiberg@webrtc.org changed reviewers:
+ henrik.lundin@webrtc.org

[kwiberg-webrtc, 2016-09-07 08:21:38]

I followed the instructions here
[http://commondatastorage.googleapis.com/chrome-infra-docs/flat/depot_tools/docs/html/git-drover.html]
to cherry-pick this CL
[https://crrev.com/d52bef7d6445070532b3c8463859ee4e1f99d70f] to M54. I was
expecting "git drover" to just upload a CL that I could send out for review, but
it also went ahead and landed it for me.

So, please review after the fact...

[hlundin-webrtc, 2016-09-07 11:58:40]

Drover is trigger-happy. You can give it options to stop at a few intermediate
places.

LGTM