Merge to XFA: Exit infinite loops for cross reference loading

Merge to XFA: Exit infinite loops for cross reference loading

When cross reference sections form a loop, our code will enter an
infinite loop. Add detection and exit code for v4 cross reference loading.
V5 loading was done previously.

TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1558093002 .

(cherry picked from commit aab8f462ea3368ed4825172231131e1a10db978d)

Committed: https://pdfium.googlesource.com/pdfium/+/c009e8e6bfefa4f77bc02ac0b359b9fe58af384f

[Wei Li, 2016-01-05 20:49:56]

clean merge, TBR

[Wei Li, 2016-01-05 20:51:36]

Description was changed from

==========
Merge to XFA: Exit infinite loops for cross reference loading

When cross reference sections form a loop, our code will enter an
infinite loop. Add detection and exit code for v4 cross reference loading.
V5 loading was done previously.

TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1558093002 .

(cherry picked from commit aab8f462ea3368ed4825172231131e1a10db978d)
==========

to

==========
Merge to XFA: Exit infinite loops for cross reference loading

When cross reference sections form a loop, our code will enter an
infinite loop. Add detection and exit code for v4 cross reference loading.
V5 loading was done previously.

TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1558093002 .

(cherry picked from commit aab8f462ea3368ed4825172231131e1a10db978d)

Committed:
https://pdfium.googlesource.com/pdfium/+/c009e8e6bfefa4f77bc02ac0b359b9fe58af...
==========

[Wei Li, 2016-01-05 20:51:37]

Committed patchset #1 (id:1) manually as
c009e8e6bfefa4f77bc02ac0b359b9fe58af384f (presubmit successful).

[Lei Zhang, 2016-01-05 22:10:11]

lgtm