Bug 1881190: Switch to a properly defined static pref for enabling of…

… UI Automation. r=nlapre

Previously, we used an undefined (and thus hidden) pref, making it more difficult to toggle.
Also, we used GetBoolPref, which is slightly less efficient.
But mostly, this is just cleaner.

Differential Revision: https://phabricator.services.mozilla.com/D202383

accessible/windows/msaa/ServiceProvider.cpp

@@ -16,7 +16,7 @@
 #include "uiaRawElmProvider.h"
 
 #include "mozilla/a11y/DocAccessibleChild.h"
-#include "mozilla/Preferences.h"
+#include "mozilla/StaticPrefs_accessibility.h"
 
 #include "ISimpleDOM.h"
 
@@ -44,7 +44,7 @@ ServiceProvider::QueryService(REFGUID aGuidService, REFIID aIID,
 
   // UIA IAccessibleEx
   if (aGuidService == IID_IAccessibleEx &&
-      Preferences::GetBool("accessibility.uia.enable") && localAcc) {
+      StaticPrefs::accessibility_uia_enable() && localAcc) {
     uiaRawElmProvider* accEx = new uiaRawElmProvider(localAcc);
     HRESULT hr = accEx->QueryInterface(aIID, aInstancePtr);
     if (FAILED(hr)) delete accEx;

modules/libpref/init/StaticPrefList.yaml

@@ -242,6 +242,12 @@
 #endif
   mirror: always
 
+# Whether to enable support for the UI Automation API on Windows.
+- name: accessibility.uia.enable
+  type: bool
+  value: false
+  mirror: always
+
 # Whether to avoid accessibility activation on Windows shortly after clipboard
 # copy.
 #