Register a default instance of FeatureList for content browser.

base/feature_list.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_FEATURE_LIST_H_
 #define BASE_FEATURE_LIST_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 109 matching lines @@
   // Returns whether the given |feature| is enabled. Must only be called after
   // the singleton instance has been registered via SetInstance(). Additionally,
   // a feature with a given name must only have a single corresponding Feature
   // struct, which is checked in builds with DCHECKs enabled.
   static bool IsEnabled(const Feature& feature);
 
   // Splits a comma-separated string containing feature names into a vector.
   static std::vector<std::string> SplitFeatureListString(
       const std::string& input);
 
+  // Initializes and sets a default instance of FeatureList if one has not yet
+  // already been set. No-op otherwise.
+  static void InitializeInstance();
+
   // Returns the singleton instance of FeatureList. Will return null until an
   // instance is registered via SetInstance().
   static FeatureList* GetInstance();
 
   // Registers the given |instance| to be the singleton feature list for this
   // process. This should only be called once and |instance| must not be null.
   static void SetInstance(scoped_ptr<FeatureList> instance);
 
   // Clears the previously-registered singleton instance for tests.
   static void ClearInstanceForTesting();
@@ skipping 65 matching lines @@
   // Whether this object has been fully initialized. This gets set to true as a
   // result of FinalizeInitialization().
   bool initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(FeatureList);
 };
 
 }  // namespace base
 
 #endif  // BASE_FEATURE_LIST_H_