[Extensions] Remove JSONFeatureProvider, SimpleFeature::Parse

extensions/common/features/simple_feature.h

Index: extensions/common/features/simple_feature.h
diff --git a/extensions/common/features/simple_feature.h b/extensions/common/features/simple_feature.h
index fb931562298d7780739ed0c411a69535105ae1cb..59db2be5cf856062e0e9aafe45421e8489aad45b 100644
--- a/extensions/common/features/simple_feature.h
+++ b/extensions/common/features/simple_feature.h
@@ -47,15 +47,6 @@ class SimpleFeature : public Feature {
   SimpleFeature();
   ~SimpleFeature() override;
 
-  // Parses the JSON representation of a feature into the fields of this object.
-  // Note: Validate() should be called after this.
-  void Parse(const base::DictionaryValue* dictionary);
-
-  // Checks whether the feature is valid. Invalid features should not be used.
-  // Subclasses can override to implement specific checking, but should always
-  // call this method as well.
-  virtual bool Validate(std::string* error);
-
   Availability IsAvailableToContext(const Extension* extension,
                                     Context context) const {
     return IsAvailableToContext(extension, context, GURL());