Remove 'WebPlugin::CheckIfRunInsecureContent'.

content/plugin/webplugin_proxy.cc

Index: content/plugin/webplugin_proxy.cc
diff --git a/content/plugin/webplugin_proxy.cc b/content/plugin/webplugin_proxy.cc
index 3d32254305467c9db5086619b451879145e2d343..f9ce4a3af074e07221ea291afeeabff3338531df 100644
--- a/content/plugin/webplugin_proxy.cc
+++ b/content/plugin/webplugin_proxy.cc
@@ -543,13 +543,6 @@ void WebPluginProxy::URLRedirectResponse(bool allow, int resource_id) {
   Send(new PluginHostMsg_URLRedirectResponse(route_id_, allow, resource_id));
 }
 
-bool WebPluginProxy::CheckIfRunInsecureContent(const GURL& url) {
-  bool result = true;
-  Send(new PluginHostMsg_CheckIfRunInsecureContent(
-      route_id_, url, &result));
-  return result;
-}
-
 #if defined(OS_WIN) && !defined(USE_AURA)
 void WebPluginProxy::UpdateIMEStatus() {
   // Retrieve the IME status from a plugin and send it to a renderer process