Move ia2_attributes handling to AXPlatformNodeWin.

ui/accessibility/platform/ax_platform_node_base.h

Index: ui/accessibility/platform/ax_platform_node_base.h
diff --git a/ui/accessibility/platform/ax_platform_node_base.h b/ui/accessibility/platform/ax_platform_node_base.h
index fa24c86798c66342b10b7eaad041e8247652a645..98aa7f5623eba9df181ac6633e19caf93761f358 100644
--- a/ui/accessibility/platform/ax_platform_node_base.h
+++ b/ui/accessibility/platform/ax_platform_node_base.h
@@ -130,6 +130,11 @@ class AX_EXPORT AXPlatformNodeBase : public AXPlatformNode {
   bool IsRichTextControl();
   bool IsRangeValueSupported() const;
 
+  // Get the range value text, which might come from aria-valuetext or
+  // a floating-point value. This is different from the value string
+  // attribute used in input controls such as text boxes and combo boxes.
+  base::string16 GetRangeValueText();
+
   // |GetInnerText| recursively includes all the text from descendants such as
   // text found in any embedded object.
   base::string16 GetInnerText();