Revert "Roll src/third_party/pdfium 726ece1b5340..0db20e0a220b (4 commits)"

This reverts commit f88d1246.

Reason for revert: prime suspect in compile failure on linux-rel

Original change's description:
> Roll src/third_party/pdfium 726ece1b5340..0db20e0a220b (4 commits)
> 
> https://pdfium.googlesource.com/pdfium.git/+log/726ece1b5340..0db20e0a220b
> 
> 
> git log 726ece1b5340..0db20e0a220b --date=short --no-merges --format='%ad %ae %s'
> 2019-05-14 thomasanderson@chromium.org Fix ODR violations in public fuzzers
> 2019-05-14 thomasanderson@chromium.org Split public fuzzer static initializer into its own file
> 2019-05-14 thomasanderson@chromium.org Add missing dependencies to fuzzers
> 2019-05-14 thomasanderson@chromium.org Move pdfium sources into fpdfsdk
> 
> 
> Created with:
>   gclient setdep -r src/third_party/pdfium@0db20e0a220b
> 
> The AutoRoll server is located here: https://autoroll.skia.org/r/pdfium-autoroll
> 
> Documentation for the AutoRoller is here:
> https://skia.googlesource.com/buildbot/+/master/autoroll/README.md
> 
> If the roll is causing failures, please contact the current sheriff, who should
> be CC'd on the roll, and stop the roller if necessary.
> 
> 
> 
> BUG=chromium:960288,chromium:960288,chromium:960288,chromium:960288
> TBR=pdfium-deps-rolls@chromium.org
> 
> Change-Id: I3d67a73b565d90cb0e2266d5a0c052b3d8c30591
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1612211
> Reviewed-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@{#659753}

TBR=chromium-autoroll@skia-public.iam.gserviceaccount.com,pdfium-deps-rolls@chromium.org

Change-Id: Ib856afb3386de711fa2ab72e858c1d08cc23e6bd
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:960288,963243
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1612259Reviewed-by: Brandon Tolsch <btolsch@chromium.org>
Commit-Queue: Brandon Tolsch <btolsch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#659765}

DEPS

@@ -153,7 +153,7 @@ 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': '0db20e0a220b9ce2ba7d6bee980ec1bcd7a667e7',
+  'pdfium_revision': '726ece1b53406b9599f5c635feae37dc7fb310c5',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.