Remove unnecessary include from checked_ptr.

Fixes chrome/builders/ci/cronet-ios-simulator-debug redness.

Bug: 1165809
Change-Id: I57f6ed9471d27b53340986bd3bbb1fc32414c1d6
Fixed: 32
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2625889Reviewed-by: Will Harris <wfh@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Mark Mentovai <mark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843183}

base/memory/checked_ptr.h

@@ -10,7 +10,6 @@
 
 #include <utility>
 
-#include "base/allocator/partition_allocator/address_pool_manager.h"
 #include "base/allocator/partition_allocator/checked_ptr_support.h"
 #include "base/allocator/partition_allocator/partition_address_space.h"
 #include "base/allocator/partition_allocator/partition_alloc_forward.h"