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

ui/views/accessibility/native_view_accessibility_auralinux.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/accessibility/native_view_accessibility_auralinux.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/memory/singleton.h"
@@ skipping 107 matching lines @@
 
   AuraLinuxApplication()
       : platform_node_(ui::AXPlatformNode::Create(this)) {
     data_.role = ui::AX_ROLE_APPLICATION;
     if (ViewsDelegate::views_delegate) {
       data_.AddStringAttribute(
           ui::AX_ATTR_NAME,
           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 {
     platform_node_->Destroy();
     platform_node_ = nullptr;
   }
 
   ui::AXPlatformNode* platform_node_;
   ui::AXNodeData data_;
   std::vector<Widget*> widgets_;
@@ skipping 17 matching lines @@
 }
 
 gfx::NativeViewAccessible NativeViewAccessibilityAuraLinux::GetParent() {
   gfx::NativeViewAccessible parent = NativeViewAccessibility::GetParent();
   if (!parent)
     parent = AuraLinuxApplication::GetInstance()->GetNativeViewAccessible();
   return parent;
 }
 
 }  // namespace views