diff --git content/browser/accessibility/accessibility_tree_formatter_win.cc content/browser/accessibility/accessibility_tree_formatter_win.cc
index 59f85adf85c3..a60cb7aa874c 100644
--- content/browser/accessibility/accessibility_tree_formatter_win.cc
+++ content/browser/accessibility/accessibility_tree_formatter_win.cc
@@ -35,7 +35,7 @@
 #include "ui/base/win/atl_module.h"
 #include "ui/gfx/win/hwnd_util.h"
 
-namespace {
+namespace internal {
 
 struct HwndWithProcId {
   HwndWithProcId(const base::ProcessId id) : pid(id), hwnd(nullptr) {}
@@ -60,7 +60,7 @@ HWND GetHwndForProcess(base::ProcessId pid) {
   return hwnd_with_proc_id.hwnd;
 }
 
-}  // namespace
+}  // namespace internal
 
 namespace content {
 
@@ -354,7 +354,7 @@ std::unique_ptr<base::DictionaryValue>
 AccessibilityTreeFormatterWin::BuildAccessibilityTreeForProcess(
     base::ProcessId pid) {
   // Get HWND for process id.
-  HWND hwnd = GetHwndForProcess(pid);
+  HWND hwnd = ::internal::GetHwndForProcess(pid);
   return BuildAccessibilityTreeForWindow(hwnd);
 }