Refactor ViewsDelegate singleton

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 7205c7a2a8c6aa768caea5320b78733d6563cbf2..37c43bb7c8ca770cfa5d26b8300ccf02b48bcc6c 100644
--- a/ui/views/accessibility/native_view_accessibility_auralinux.cc
+++ b/ui/views/accessibility/native_view_accessibility_auralinux.cc
@@ -119,17 +119,17 @@ class AuraLinuxApplication
   AuraLinuxApplication()
       : platform_node_(ui::AXPlatformNode::Create(this)) {
     data_.role = ui::AX_ROLE_APPLICATION;
-    if (ViewsDelegate::views_delegate) {
+    if (ViewsDelegate::GetInstance()) {
       data_.AddStringAttribute(
           ui::AX_ATTR_NAME,
-          ViewsDelegate::views_delegate->GetApplicationName());
+          ViewsDelegate::GetInstance()->GetApplicationName());
     }
     ui::AXPlatformNodeAuraLinux::SetApplication(platform_node_);
-    if (ViewsDelegate::views_delegate) {
+    if (ViewsDelegate::GetInstance()) {
       // This should be on the a blocking pool thread so that we can open
       // libatk-bridge.so without blocking this thread.
       scoped_refptr<base::TaskRunner> init_task_runner =
-          ViewsDelegate::views_delegate->GetBlockingPoolTaskRunner();
+          ViewsDelegate::GetInstance()->GetBlockingPoolTaskRunner();
       if (init_task_runner)
         ui::AXPlatformNodeAuraLinux::StaticInitialize(init_task_runner);
     }