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

chrome/browser/ui/views/chrome_views_delegate.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_CHROME_VIEWS_DELEGATE_H_
 #define CHROME_BROWSER_UI_VIEWS_CHROME_VIEWS_DELEGATE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "build/build_config.h"
@@ skipping 31 matching lines @@
   void AddRef() override;
   void ReleaseRef() override;
   void OnBeforeWidgetInit(
       views::Widget::InitParams* params,
       views::internal::NativeWidgetDelegate* delegate) override;
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
   bool WindowManagerProvidesTitleBar(bool maximized) override;
 #endif
   ui::ContextFactory* GetContextFactory() override;
   std::string GetApplicationName() override;
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+  scoped_refptr<base::TaskRunner>
+      GetTaskRunnerForAuraLinuxAccessibilityInit() override;
+#endif
 #if defined(OS_WIN)
   virtual int GetAppbarAutohideEdges(HMONITOR monitor,
                                      const base::Closure& callback) override;
 #endif
 
  private:
 #if defined(OS_WIN)
   typedef std::map<HMONITOR, int> AppbarAutohideEdgeMap;
 
   // Callback on main thread with the edges. |returned_edges| is the value that
@@ skipping 15 matching lines @@
   // GetAutohideEdges().start a new query.
   bool in_autohide_edges_callback_;
 
   base::WeakPtrFactory<ChromeViewsDelegate> weak_factory_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ChromeViewsDelegate);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_CHROME_VIEWS_DELEGATE_H_