Adds API for testing aria-controls/flowto/owns properties.

content/shell/renderer/test_runner/web_ax_object_proxy.h

Index: content/shell/renderer/test_runner/web_ax_object_proxy.h
diff --git a/content/shell/renderer/test_runner/web_ax_object_proxy.h b/content/shell/renderer/test_runner/web_ax_object_proxy.h
index 6c734b688c4475bd744e3c7fd173945d067444bb..1a800be5b3f9560c197cd07ed26c8d0f38e861b5 100644
--- a/content/shell/renderer/test_runner/web_ax_object_proxy.h
+++ b/content/shell/renderer/test_runner/web_ax_object_proxy.h
@@ -99,6 +99,9 @@ class WebAXObjectProxy : public gin::Wrappable<WebAXObjectProxy> {
   bool IsButtonStateMixed();
 
   // Bound methods.
+  v8::Handle<v8::Object> AriaControlsElementAtIndex(unsigned index);
+  v8::Handle<v8::Object> AriaFlowToElementAtIndex(unsigned index);
+  v8::Handle<v8::Object> AriaOwnsElementAtIndex(unsigned index);
   std::string AllAttributes();
   std::string AttributesOfChildren();
   int LineForIndex(int index);