Add more checks to tiff_read() and tiff_seek().

Add more checks to tiff_read() and tiff_seek().

BUG=chromium:659519
Committed: https://pdfium.googlesource.com/pdfium/+/cd5f026e7b277ec73d53e149c7c48ee981547d1a

[Lei Zhang, 2016-10-26 18:46:50]

The CQ bit was checked by thestig@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-10-26 18:46:55]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Lei Zhang, 2016-10-26 18:50:56]

thestig@chromium.org changed reviewers:
+ tsepez@chromium.org

[commit-bot: I haz the power, 2016-10-26 19:01:26]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-10-26 19:01:27]

Dry run: This issue passed the CQ dry run.

[Tom Sepez, 2016-10-26 20:20:11]

lgtm

[Lei Zhang, 2016-10-26 20:41:02]

The CQ bit was checked by thestig@chromium.org

[commit-bot: I haz the power, 2016-10-26 20:41:12]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-26 20:41:28]

Description was changed from

==========
Add more checks to tiff_read() and tiff_seek().

BUG=chromium:659519
==========

to

==========
Add more checks to tiff_read() and tiff_seek().

BUG=chromium:659519

Committed:
https://pdfium.googlesource.com/pdfium/+/cd5f026e7b277ec73d53e149c7c48ee98154...
==========

[commit-bot: I haz the power, 2016-10-26 20:41:29]

Committed patchset #1 (id:1) as
https://pdfium.googlesource.com/pdfium/+/cd5f026e7b277ec73d53e149c7c48ee98154...