Pass a TaskRunner through ViewsDelegate to put AX init on FILE thread

ui/views/accessibility/native_view_accessibility_auralinux.cc

Index: ui/views/accessibility/native_view_accessibility_auralinux.cc
diff --git a/ui/views/accessibility/native_view_accessibility_auralinux.cc b/ui/views/accessibility/native_view_accessibility_auralinux.cc
index afee5352cd08068e26ab33d2a827ff6dbdbab564..57907fc2e9323ef1210581e0c4a4791b8db9d261 100644
--- a/ui/views/accessibility/native_view_accessibility_auralinux.cc
+++ b/ui/views/accessibility/native_view_accessibility_auralinux.cc
@@ -125,6 +125,10 @@ class AuraLinuxApplication
           ViewsDelegate::views_delegate->GetApplicationName());
     }
     ui::AXPlatformNodeAuraLinux::SetApplication(platform_node_);
+    scoped_refptr<base::TaskRunner> init_task_runner =
+        ViewsDelegate::views_delegate->GetInitializationTaskRunner();
+    if (init_task_runner)
+      ui::AXPlatformNodeAuraLinux::StaticInitialize(init_task_runner);
   }
 
   ~AuraLinuxApplication() override {