Register a default instance of FeatureList for content browser.

base/feature_list.cc

Index: base/feature_list.cc
diff --git a/base/feature_list.cc b/base/feature_list.cc
index 38cdf57c139ff5812ae3063e6e5e74f140750322..050c5aa2d161c302f74b9a3b839df3cece050673 100644
--- a/base/feature_list.cc
+++ b/base/feature_list.cc
@@ -95,6 +95,13 @@ std::vector<std::string> FeatureList::SplitFeatureListString(
 }
 
 // static
+void FeatureList::InitializeInstance() {
+  if (g_instance)
+    return;
+  SetInstance(make_scoped_ptr(new FeatureList));
+}
+
+// static
 FeatureList* FeatureList::GetInstance() {
   return g_instance;
 }