Move ia2_attributes handling to AXPlatformNodeWin.

ui/accessibility/platform/ax_platform_node_base.cc

Index: ui/accessibility/platform/ax_platform_node_base.cc
diff --git a/ui/accessibility/platform/ax_platform_node_base.cc b/ui/accessibility/platform/ax_platform_node_base.cc
index 855aaadf3b9d351c9ddaa610935f38db4ccb040c..e16ba20c0847e8b55314d7cd5f2d3c3badc29ee5 100644
--- a/ui/accessibility/platform/ax_platform_node_base.cc
+++ b/ui/accessibility/platform/ax_platform_node_base.cc
@@ -4,6 +4,7 @@
 
 #include "ui/accessibility/platform/ax_platform_node_base.h"
 
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_action_data.h"
 #include "ui/accessibility/ax_node_data.h"
@@ -337,6 +338,16 @@ bool AXPlatformNodeBase::IsRangeValueSupported() const {
   }
 }
 
+base::string16 AXPlatformNodeBase::GetRangeValueText() {
+  float fval;
+  base::string16 value = GetString16Attribute(ui::AX_ATTR_VALUE);
+
+  if (value.empty() && GetFloatAttribute(ui::AX_ATTR_VALUE_FOR_RANGE, &fval)) {
+    value = base::UTF8ToUTF16(base::DoubleToString(fval));
+  }
+  return value;
+}
+
 AXPlatformNodeBase* AXPlatformNodeBase::GetTable() const {
   if (!delegate_)
     return nullptr;