Reduce size of generated extension FeatureProviders.

extensions/common/features/base_feature_provider.cc

Index: extensions/common/features/base_feature_provider.cc
diff --git a/extensions/common/features/base_feature_provider.cc b/extensions/common/features/base_feature_provider.cc
index 99b8bb423edd573b5ea84568cc09017c712c64f7..adc463cc04e9b6a54542995d055c5aee1ec860b6 100644
--- a/extensions/common/features/base_feature_provider.cc
+++ b/extensions/common/features/base_feature_provider.cc
@@ -4,6 +4,8 @@
 
 #include "extensions/common/features/base_feature_provider.h"
 
+#include <utility>
+
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "extensions/common/features/feature.h"
@@ -59,4 +61,9 @@ std::vector<Feature*> BaseFeatureProvider::GetChildren(const Feature& parent)
   return result;
 }
 
+void BaseFeatureProvider::AddFeature(base::StringPiece name,
+                                     std::unique_ptr<Feature> feature) {
+  features_[name.as_string()] = std::move(feature);
+}
+
 }  // namespace extensions