Reduce string copies in GURL creation

chrome/renderer/plugins/chrome_plugin_placeholder.cc

Index: chrome/renderer/plugins/chrome_plugin_placeholder.cc
diff --git a/chrome/renderer/plugins/chrome_plugin_placeholder.cc b/chrome/renderer/plugins/chrome_plugin_placeholder.cc
index 6f616672312e7b4b4c255697e67871f727ac3844..c2a854f6db37783b8ddffa3fd5baa6d1c5232cee 100644
--- a/chrome/renderer/plugins/chrome_plugin_placeholder.cc
+++ b/chrome/renderer/plugins/chrome_plugin_placeholder.cc
@@ -19,6 +19,7 @@
 #include "chrome/renderer/plugins/plugin_preroller.h"
 #include "chrome/renderer/plugins/plugin_uma.h"
 #include "components/content_settings/content/common/content_settings_messages.h"
+#include "content/public/child/url_conversion.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/context_menu_params.h"
 #include "content/public/renderer/render_frame.h"
@@ -262,7 +263,7 @@ void ChromePluginPlaceholder::PluginListChanged() {
   render_frame()->Send(
       new ChromeViewHostMsg_GetPluginInfo(routing_id(),
                                           GURL(GetPluginParams().url),
-                                          GURL(top_origin),
+                                          content::WebStringToGURL(top_origin),
                                           mime_type,
                                           &output));
   if (output.status == status_)