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

chrome/browser/ui/views/chrome_views_delegate.cc

 // 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.
 
 #include "chrome/browser/ui/views/chrome_views_delegate.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser_window_state.h"
 #include "chrome/common/chrome_version_info.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/context_factory.h"
 #include "grit/chrome_unscaled_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_switches.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/widget/native_widget.h"
 #include "ui/views/widget/widget.h"
 
 #if defined(OS_WIN)
@@ skipping 354 matching lines @@
 #endif
 
 ui::ContextFactory* ChromeViewsDelegate::GetContextFactory() {
   return content::GetContextFactory();
 }
 
 std::string ChromeViewsDelegate::GetApplicationName() {
   return chrome::VersionInfo().Name();
 }
 
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+scoped_refptr<base::TaskRunner>
+    ChromeViewsDelegate::GetTaskRunnerForAuraLinuxAccessibilityInit() {
+  // This should be on the FILE thread so that we can open libatk-bridge.so
+  // without blocking.
+  return content::BrowserThread::GetMessageLoopProxyForThread(
+      content::BrowserThread::FILE);
+}
+#endif
+
 #if defined(OS_WIN)
 int ChromeViewsDelegate::GetAppbarAutohideEdges(HMONITOR monitor,
                                                 const base::Closure& callback) {
   // Initialize the map with EDGE_BOTTOM. This is important, as if we return an
   // initial value of 0 (no auto-hide edges) then we'll go fullscreen and
   // windows will automatically remove WS_EX_TOPMOST from the appbar resulting
   // in us thinking there is no auto-hide edges. By returning at least one edge
   // we don't initially go fullscreen until we figure out the real auto-hide
   // edges.
   if (!appbar_autohide_edge_map_.count(monitor))
@@ skipping 27 matching lines @@
 }
 #endif
 
 #if !defined(USE_AURA) && !defined(USE_CHROMEOS)
 views::Widget::InitParams::WindowOpacity
 ChromeViewsDelegate::GetOpacityForInitParams(
     const views::Widget::InitParams& params) {
   return views::Widget::InitParams::OPAQUE_WINDOW;
 }
 #endif