Roll PDFium from f7a0128b9441 to cb9160484da5 (3 revisions)

https://pdfium.googlesource.com/pdfium.git/+log/f7a0128b9441..cb9160484da5

2020-09-25 tsepez@chromium.org Use Optional<> return from CXFA_LocaleMgr::GetConfigLocaleName().
2020-09-25 tsepez@chromium.org Introduce common superclass GCedLocaleIface
2020-09-25 tsepez@chromium.org Garbage collect CXFA_LocaleMgr.

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/pdfium-autoroll
Please CC pdfium-deps-rolls@chromium.org on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Bug: None
Tbr: pdfium-deps-rolls@chromium.org
Change-Id: I1b468e9fbcbb3e5d0fde4fd25b9bf8e453fea3ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2433072Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#810947}

DEPS

@@ -215,7 +215,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.
-  'pdfium_revision': 'f7a0128b944120aa4e0427484bfe1c22604e23c2',
+  'pdfium_revision': 'cb9160484da5df0381a1b3b2811cc0ae397917cd',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.