Added a check for the utf8 string input being empty (NULL).

chrome/renderer/external_extension.cc

Index: chrome/renderer/external_extension.cc
diff --git a/chrome/renderer/external_extension.cc b/chrome/renderer/external_extension.cc
index f10133315a671450a5e2030e54601d0457433518..26c779bf0134609670feb9f368bfc361794b0be8 100644
--- a/chrome/renderer/external_extension.cc
+++ b/chrome/renderer/external_extension.cc
@@ -143,10 +143,10 @@ v8::Handle<v8::Value> ExternalExtensionWrapper::AddSearchProvider(
 v8::Handle<v8::Value> ExternalExtensionWrapper::IsSearchProviderInstalled(
     const v8::Arguments& args) {
   if (!args.Length()) return v8::Undefined();
+  v8::String::Utf8Value utf8name(args[0]);
+  if (!utf8name.length()) return v8::Undefined();
 
-  std::string name = std::string(*v8::String::Utf8Value(args[0]));
-  if (!name.length()) return v8::Undefined();
-
+  std::string name = std::string(*utf8name);
   RenderView* render_view = GetRenderView();
   if (!render_view) return v8::Undefined();