Make AXPlatformNodeDelegate::GetData() const

ui/views/accessibility/native_view_accessibility_base.h

Index: ui/views/accessibility/native_view_accessibility_base.h
diff --git a/ui/views/accessibility/native_view_accessibility_base.h b/ui/views/accessibility/native_view_accessibility_base.h
index 6606a105a62eb28fc55212631a245a39c38508e3..36fd0ad09125519498462e803f3ff3f0cb362b8b 100644
--- a/ui/views/accessibility/native_view_accessibility_base.h
+++ b/ui/views/accessibility/native_view_accessibility_base.h
@@ -40,7 +40,7 @@ class VIEWS_EXPORT NativeViewAccessibilityBase
   bool SetFocused(bool focused);
 
   // ui::AXPlatformNodeDelegate
-  const ui::AXNodeData& GetData() override;
+  const ui::AXNodeData& GetData() const override;
   int GetChildCount() override;
   gfx::NativeViewAccessible ChildAtIndex(int index) override;
   gfx::NativeWindow GetTopLevelWidget() override;
@@ -76,7 +76,7 @@ class VIEWS_EXPORT NativeViewAccessibilityBase
   // a scoped_ptr. It is dereferenced in the destructor.
   ui::AXPlatformNode* ax_node_;
 
-  ui::AXNodeData data_;
+  mutable ui::AXNodeData data_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibilityBase);
 };