Roll base/allocator/partition_allocator/ c2bb1848e..c702699cc (26 commits)

Set `assert_cpp20_default` GN variable to make this build.

https://chromium.googlesource.com/chromium/src/base/allocator/partition_allocator.git/+log/c2bb1848ed49..c702699cceb4

Created with:
  roll-dep base/allocator/partition_allocator

Change-Id: I6058f6017d673fff8c1f534c64c0d79242268db3
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/117354
Reviewed-by: Thomas Sepez <tsepez@google.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/DEPS b/DEPS
index c3d6ef2..8253cd1 100644
--- a/DEPS
+++ b/DEPS
@@ -163,7 +163,7 @@
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling partition_allocator
   # and whatever else without interference from each other.
-  'partition_allocator_revision': 'c2bb1848ed490e596de26b28c9f9760d9b4ef387',
+  'partition_allocator_revision': 'c702699cceb42a9b43296000129f46a8a419651c',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling pdfium_tests
   # and whatever else without interference from each other.
diff --git a/build_overrides/partition_alloc.gni b/build_overrides/partition_alloc.gni
index 3ed38af..521c6fa 100644
--- a/build_overrides/partition_alloc.gni
+++ b/build_overrides/partition_alloc.gni
@@ -53,3 +53,7 @@
 raw_ptr_zero_on_construct_default = true
 raw_ptr_zero_on_move_default = true
 raw_ptr_zero_on_destruct_default = false
+
+# Allow embedders to opt-out of C++20 build which is set as default.
+# Set to true to use C++20 by default.
+assert_cpp20_default = true