mac: Make mach_o_image_reader_mac_unittest.cc build with the MacOSX11.sdk.

PAGE_SIZE now needs an explicit include of mac/vm_param.h.

Bug: 1098738
Change-Id: Ib56e3b080919edb08aa12aeae0fe3357d5022881
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2264255
Auto-Submit: Nico Weber <thakis@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781881}

chrome/common/safe_browsing/mach_o_image_reader_mac_unittest.cc

@@ -8,6 +8,7 @@
 #include <libkern/OSByteOrder.h>
 #include <mach-o/fat.h>
 #include <mach-o/loader.h>
+#include <mach/vm_param.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>