Revert of Fix loading accessibility tree for child frame that's already loaded.

content/renderer/accessibility/render_accessibility_impl.cc

Index: content/renderer/accessibility/render_accessibility_impl.cc
diff --git a/content/renderer/accessibility/render_accessibility_impl.cc b/content/renderer/accessibility/render_accessibility_impl.cc
index b4ee843bb8a451bf23b83a65bcc28708764622bc..64e9f6e6b72aa03d7fcf0d9c48d0f4aad818472b 100644
--- a/content/renderer/accessibility/render_accessibility_impl.cc
+++ b/content/renderer/accessibility/render_accessibility_impl.cc
@@ -75,6 +75,15 @@
       ack_pending_(false),
       reset_token_(0),
       weak_factory_(this) {
+  // There's only one AXObjectCache for the root of a local frame tree,
+  // so if this frame's parent is local we can safely do nothing.
+  if (render_frame_ &&
+      render_frame_->GetWebFrame() &&
+      render_frame_->GetWebFrame()->parent() &&
+      render_frame_->GetWebFrame()->parent()->isWebLocalFrame()) {
+    return;
+  }
+
   WebView* web_view = render_frame_->GetRenderView()->GetWebView();
   WebSettings* settings = web_view->settings();
   settings->setAccessibilityEnabled(true);