Implement API features for the Extension API feature system

chrome/common/extensions/features/manifest_feature.cc

Index: chrome/common/extensions/features/manifest_feature.cc
diff --git a/chrome/common/extensions/features/manifest_feature.cc b/chrome/common/extensions/features/manifest_feature.cc
index 51d9fd51d5c39746fa52d00b74f5f0b0b3d6a1e5..be60699937e32f68265a009b2662a0ea4114a2db 100644
--- a/chrome/common/extensions/features/manifest_feature.cc
+++ b/chrome/common/extensions/features/manifest_feature.cc
@@ -34,4 +34,21 @@ Feature::Availability ManifestFeature::IsAvailableToContext(
   return CreateAvailability(IS_AVAILABLE);
 }
 
+bool ManifestFeature::Parse(const DictionaryValue* value) {
+  if (!SimpleFeature::Parse(value))
+    return false;
+
+  if (extension_types()->empty()) {
+    LOG(ERROR) << name() << ": Manifest features must specify at least one "
+               << "value for extension_types.";
+    return false;
+  }
+
+  if (!GetContexts()->empty()) {
+    LOG(ERROR) << name() << ": Manifest features do not support contexts.";
+    return false;
+  }
+  return true;
+}
+
 }  // namespace