Rewrite raw pointer fields to use raw_ptr<T> for cros

This reapplies the rewrite_raw_ptr_fields rewriter on cros platform.

This change is a merge of the following changes:
PS1 raw_ptr rewrite generated by
    rewrite-multiple-platforms.sh cros
    on 80b036835cb551cea5374c45d2e5dff74e60bd37
    with crrev.com/c/3726431
PS2 Unrewrite and exclude field in base/check.h to avoid cyclic include
PS3 Fix compile errors caused by NULL
PS4 Add missing .get()
PS5 Add missing .get()

Bug: 1073933
Change-Id: Ia042236c6c39f22ea1c96cb5b14ea68961c10534
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3731468
Reviewed-by: Bartek Nowierski <[email protected]>
Commit-Queue: Keishi Hattori <[email protected]>
Owners-Override: Keishi Hattori <[email protected]>
Owners-Override: Bartek Nowierski <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1018553}
diff --git a/chrome/browser/net/nss_service.h b/chrome/browser/net/nss_service.h
index 8914d0e7f..dc74a9d 100644
--- a/chrome/browser/net/nss_service.h
+++ b/chrome/browser/net/nss_service.h
@@ -8,6 +8,7 @@
 #include <memory>
 
 #include "base/callback.h"
+#include "base/memory/raw_ptr.h"
 #include "build/buildflag.h"
 #include "build/chromeos_buildflags.h"
 #include "components/keyed_service/core/keyed_service.h"
@@ -69,7 +70,7 @@
   // destroyed exclusively on the IO thread.
   std::unique_ptr<NSSCertDatabaseChromeOSManager> nss_cert_database_manager_;
 #elif BUILDFLAG(IS_CHROMEOS_LACROS)
-  content::BrowserContext* context_;
+  raw_ptr<content::BrowserContext> context_;
 #endif
 };