Reland of Further reduction of feature_compiler.py generated code

extensions/common/features/complex_feature.h

Index: extensions/common/features/complex_feature.h
diff --git a/extensions/common/features/complex_feature.h b/extensions/common/features/complex_feature.h
index 7b63ae6f957b08809537c9ac8891ddc51dc9db66..9ccbd4fec4aecffe3ac5774bae84f3d7a00ac00f 100644
--- a/extensions/common/features/complex_feature.h
+++ b/extensions/common/features/complex_feature.h
@@ -23,9 +23,8 @@
 // available, but not if only some combination of Features is available.
 class ComplexFeature : public Feature {
  public:
-  using FeatureList = std::vector<std::unique_ptr<Feature>>;
-
-  explicit ComplexFeature(std::unique_ptr<FeatureList> features);
+  // Takes ownership of Feature*s contained in |features|.
+  explicit ComplexFeature(std::vector<Feature*>* features);
   ~ComplexFeature() override;
 
   // extensions::Feature:
@@ -50,6 +49,7 @@
  private:
   FRIEND_TEST_ALL_PREFIXES(FeaturesGenerationTest, FeaturesTest);
 
+  using FeatureList = std::vector<std::unique_ptr<Feature>>;
   FeatureList features_;
 
   DISALLOW_COPY_AND_ASSIGN(ComplexFeature);