Change ScopedFeatureList to overrides FeatureList not reset

base/test/scoped_feature_list.h

Index: base/test/scoped_feature_list.h
diff --git a/base/test/scoped_feature_list.h b/base/test/scoped_feature_list.h
index 99e07f5374a96bf9668e9805da592cc9cd4e5805..e1df6c6ad7050748d47882bfeecc5e577233d6a4 100644
--- a/base/test/scoped_feature_list.h
+++ b/base/test/scoped_feature_list.h
@@ -22,29 +22,42 @@ class ScopedFeatureList final {
   ScopedFeatureList();
   ~ScopedFeatureList();
 
+  // WARNING: This method will reset any globally configured features to their
+  // default values, which can hide feature interaction bugs. Please use
+  // sparingly.  https://crbug.com/713390
   // Initializes and registers a FeatureList instance with no overrides.
   void Init();
 
+  // WARNING: This method will reset any globally configured features to their
+  // default values, which can hide feature interaction bugs. Please use
+  // sparingly.  https://crbug.com/713390
   // Initializes and registers the given FeatureList instance.
   void InitWithFeatureList(std::unique_ptr<FeatureList> feature_list);
 
-  // Initializes and registers a FeatureList instance with the given enabled
-  // and disabled features.
-  void InitWithFeatures(
-      const std::initializer_list<base::Feature>& enabled_features,
-      const std::initializer_list<base::Feature>& disabled_features);
-
-  // Initializes and registers a FeatureList instance with the given
+  // WARNING: This method will reset any globally configured features to their
+  // default values, which can hide feature interaction bugs. Please use
+  // sparingly.  https://crbug.com/713390
+  // Initializes and registers a FeatureList instance with only the given
   // enabled and disabled features (comma-separated names).
   void InitFromCommandLine(const std::string& enable_features,
                            const std::string& disable_features);
 
-  // Initializes and registers a FeatureList instance enabling a single
-  // feature.
+  // Initializes and registers a FeatureList instance based on present
+  // FeatureList and overridden with the given enabled and disabled features.
+  // Any feature overrides already present in the global FeatureList will
+  // continue to apply, unless they conflict with the overrides passed into this
+  // method. This is important for testing potentially unexpected feature
+  // interactions.
+  void InitWithFeatures(
+      const std::initializer_list<base::Feature>& enabled_features,
+      const std::initializer_list<base::Feature>& disabled_features);
+
+  // Initializes and registers a FeatureList instance based on present
+  // FeatureList and overridden with single enabled feature.
   void InitAndEnableFeature(const base::Feature& feature);
 
-  // Initializes and registers a FeatureList instance disabling a single
-  // feature.
+  // Initializes and registers a FeatureList instance based on present
+  // FeatureList and overridden with single disabled feature.
   void InitAndDisableFeature(const base::Feature& feature);
 
  private: