Reduce string copies in GURL creation

chrome/renderer/extensions/media_galleries_custom_bindings.cc

Index: chrome/renderer/extensions/media_galleries_custom_bindings.cc
diff --git a/chrome/renderer/extensions/media_galleries_custom_bindings.cc b/chrome/renderer/extensions/media_galleries_custom_bindings.cc
index 16d0b4aee15381e42d9aa0781b0a1a56af784779..a9f4cab53fe8a281944df31dc3dca93c94cf4a63 100644
--- a/chrome/renderer/extensions/media_galleries_custom_bindings.cc
+++ b/chrome/renderer/extensions/media_galleries_custom_bindings.cc
@@ -8,6 +8,7 @@
 
 #include "extensions/renderer/script_context.h"
 #include "storage/common/fileapi/file_system_util.h"
+#include "third_party/WebKit/public/platform/URLConversion.h"
 #include "third_party/WebKit/public/web/WebDOMFileSystem.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
@@ -36,7 +37,8 @@ void MediaGalleriesCustomBindings::GetMediaFileSystemObject(
 
   blink::WebLocalFrame* webframe =
       blink::WebLocalFrame::frameForCurrentContext();
-  const GURL origin = GURL(webframe->document().securityOrigin().toString());
+  const GURL origin =
+      blink::WebStringToGURL(webframe->document().securityOrigin().toString());
   std::string fs_name =
       storage::GetFileSystemName(origin, storage::kFileSystemTypeExternal);
   fs_name.append("_");