Implement API features for the Extension API feature system

chrome/common/extensions/features/permission_feature.cc

Index: chrome/common/extensions/features/permission_feature.cc
diff --git a/chrome/common/extensions/features/permission_feature.cc b/chrome/common/extensions/features/permission_feature.cc
index 1f5da626995751a25540285db3da55a47a772af0..c4970946895ea69207f211cc552011681d955d33 100644
--- a/chrome/common/extensions/features/permission_feature.cc
+++ b/chrome/common/extensions/features/permission_feature.cc
@@ -36,4 +36,21 @@ Feature::Availability PermissionFeature::IsAvailableToContext(
   return CreateAvailability(IS_AVAILABLE);
 }
 
+bool PermissionFeature::Parse(const DictionaryValue* value) {
+  if (!SimpleFeature::Parse(value))
+    return false;
+
+  if (extension_types()->empty()) {
+    LOG(ERROR) << name() << ": Permission features must specify at least one "
+               << "value for extension_types.";
+    return false;
+  }
+
+  if (!GetContexts()->empty()) {
+    LOG(ERROR) << name() << ": Permission features do not support contexts.";
+    return false;
+  }
+  return true;
+}
+
 }  // namespace