Move StartsWith[ASCII] to base namespace.

chrome/installer/gcapi/gcapi_omaha_experiment.cc

Index: chrome/installer/gcapi/gcapi_omaha_experiment.cc
diff --git a/chrome/installer/gcapi/gcapi_omaha_experiment.cc b/chrome/installer/gcapi/gcapi_omaha_experiment.cc
index c49de3d34353007b108cfb065f1f44abb33ff0ad..30c013763c433e5db63b8e5ed8ed1821e28d0712 100644
--- a/chrome/installer/gcapi/gcapi_omaha_experiment.cc
+++ b/chrome/installer/gcapi/gcapi_omaha_experiment.cc
@@ -50,7 +50,7 @@ bool SetExperimentLabel(const wchar_t* brand_code,
   base::string16 new_labels;
   for (std::vector<base::string16>::const_iterator it = entries.begin();
        it != entries.end(); ++it) {
-    if (!it->empty() && !StartsWith(*it, label + L"=", true)) {
+    if (!it->empty() && !base::StartsWith(*it, label + L"=", true)) {
       new_labels += *it;
       new_labels += google_update::kExperimentLabelSeparator;
     }