Bump up `kMaxFormLevel`.

It's the simpliest way to make the PDF in question render, as it has
more than 30 levels of form xobjects.

Bug: chromium:972999
Change-Id: I84a1f65b86a8d50057a00d62ae15b03d1e6ceb0a
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/74911
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Hui Yingst <nigi@chromium.org>

core/fpdfapi/page/cpdf_streamcontentparser.cpp

diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.cpp b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
index 89451d3..82b0ddf 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
@@ -43,7 +43,7 @@
 
 namespace {
 
-const int kMaxFormLevel = 30;
+const int kMaxFormLevel = 40;
 
 const int kSingleCoordinatePair = 1;
 const int kTensorCoordinatePairs = 16;

testing/SUPPRESSIONS

diff --git a/testing/SUPPRESSIONS b/testing/SUPPRESSIONS
index f14aa19..c9e7369 100644
--- a/testing/SUPPRESSIONS
+++ b/testing/SUPPRESSIONS
@@ -349,9 +349,6 @@
 # TODO(chromium:451366): Remove after associated bug is fixed
 bug_451366.in * * *
 
-# TODO(chromium:972999): Remove after associated bug is fixed
-bug_972999.in * * *
-
 # TODO(chromium:1028991): Remove after associated bug is fixed
 reset_button.in * * *