Enable PDF accessibility when RenderFrame's accessibility mode changes.

content/renderer/pepper/pepper_plugin_instance_impl.cc

Index: content/renderer/pepper/pepper_plugin_instance_impl.cc
diff --git a/content/renderer/pepper/pepper_plugin_instance_impl.cc b/content/renderer/pepper/pepper_plugin_instance_impl.cc
index 29625e4a049ad9d5f3e9ebfd89b88307133d92e3..f0dfaa144133b6b979b3d1e468ab309ab6f3f689 100644
--- a/content/renderer/pepper/pepper_plugin_instance_impl.cc
+++ b/content/renderer/pepper/pepper_plugin_instance_impl.cc
@@ -2131,6 +2131,11 @@ bool PepperPluginInstanceImpl::PrepareTextureMailbox(
                                                             release_callback);
 }
 
+void PepperPluginInstanceImpl::AccessibilityModeChanged() {
+  if (render_frame_->render_accessibility() && LoadPdfInterface())
+    plugin_pdf_interface_->EnableAccessibility(pp_instance());
+}
+
 void PepperPluginInstanceImpl::OnDestruct() { render_frame_ = NULL; }
 
 void PepperPluginInstanceImpl::OnThrottleStateChange() {