[A11y] AX_FAIL_FAST_BUILD() as precompiled function

Avoids incorrect result when developer forgets to include ax_common.h.

Bug: none
Change-Id: Id7a4fe2213ea2db17b940c46d10a2069f50e6bf7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6068266
Reviewed-by: Jocelyn Tran <[email protected]>
Commit-Queue: Ken Buchanan <[email protected]>
Auto-Submit: Aaron Leventhal <[email protected]>
Reviewed-by: Ken Buchanan <[email protected]>
Reviewed-by: Nektarios Paisios <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1392519}
diff --git a/ui/accessibility/ax_tree.h b/ui/accessibility/ax_tree.h
index d6efc60..f4254848 100644
--- a/ui/accessibility/ax_tree.h
+++ b/ui/accessibility/ax_tree.h
@@ -269,7 +269,7 @@
   // `SetFocusedNodeShouldNeverBeIgnored` above).
   static bool is_focused_node_always_unignored_;
 
-#if defined(AX_FAIL_FAST_BUILD)
+#if AX_FAIL_FAST_BUILD()
   void CheckTreeConsistency(const AXTreeUpdate& update);
 #endif