[Network/SSL] Make |ScopedChapsLoadFixup| STACK_ALLOCATED()

- Annotate |ScopedChapsLoadFixup| with STACK_ALLOCATED();
- Exclude |ScopedChapsLoadFixup::chaps_handle_| from raw pointer usage
  check.

I missed this field during the automatic rewrite crrev.com/c/4607774 .
Adding the exclusion annotation to make compilation success with
|is_component_build = true|.

Context: 
Change-Id: I425d34938b0cea68f3fdc23bc799791f97ff851f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4625702
Reviewed-by: Keishi Hattori <keishi@chromium.org>
Reviewed-by: Adam Langley <agl@chromium.org>
Commit-Queue: Mikihito Matsuura <mikt@google.com>
Cr-Commit-Position: refs/heads/main@{#1159607}

crypto/chaps_support.cc

@@ -9,6 +9,8 @@
 #include <secmodt.h>
 
 #include "base/logging.h"
+#include "base/memory/raw_ptr_exclusion.h"
+#include "base/memory/stack_allocated.h"
 #include "base/threading/scoped_blocking_call.h"
 #include "crypto/scoped_nss_types.h"
 #include "nss_util_internal.h"
@@ -22,13 +24,18 @@ const char kChapsModuleName[] = "Chaps";
 const char kChapsPath[] = "libchaps.so";
 
 class ScopedChapsLoadFixup {
+  STACK_ALLOCATED();
+
  public:
   ScopedChapsLoadFixup();
   ~ScopedChapsLoadFixup();
 
  private:
 #if defined(COMPONENT_BUILD)
-  void* chaps_handle_;
+  // This field stores a handle and is not a pointer to PA memory.
+  // Also, this class is always stack-allocated and visibility is limited.
+  // Hence no benefit from using raw_ptr<void>.
+  RAW_PTR_EXCLUSION void* chaps_handle_;
 #endif
 };