Revert "Remove webkit_glue::BuildUserAgent(), change the contract in webkit_glue"

webkit/support/webkit_support_glue.cc

Index: webkit/support/webkit_support_glue.cc
diff --git a/webkit/support/webkit_support_glue.cc b/webkit/support/webkit_support_glue.cc
index 705c80d39816a7e6bddc5af25b96667b1c3917d8..49be72a014b563c88aa4a50538bd3cd32ce824fc 100644
--- a/webkit/support/webkit_support_glue.cc
+++ b/webkit/support/webkit_support_glue.cc
@@ -48,6 +48,11 @@ bool IsProtocolSupportedForMedia(const GURL& url) {
   return false;
 }
 
+std::string BuildUserAgent(bool mimic_windows) {
+  return webkit_glue::BuildUserAgentHelper(mimic_windows,
+                                           "DumpRenderTree/0.0.0.0");
+}
+
 bool GetPluginFinderURL(std::string* plugin_finder_url) {
   return false;
 }