Unknown options in extension manifest file are silently ignored

chrome/common/extensions/manifest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/extensions/manifest.h"
 
 #include "base/basictypes.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/string_split.h"
+#include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "chrome/common/extensions/extension_error_utils.h"
 #include "chrome/common/extensions/simple_feature_provider.h"
 
 namespace errors = extension_manifest_errors;
 namespace keys = extension_manifest_keys;
 
 namespace extensions {
 
@@ skipping 49 matching lines @@
       continue;
 
     Feature* feature =
         SimpleFeatureProvider::GetManifestFeatures()->GetFeature(*feature_name);
     Feature::Availability result = feature->IsAvailableToManifest(
         extension_id_, type_, Feature::ConvertLocation(location_),
         GetManifestVersion());
     if (result != Feature::IS_AVAILABLE)
       warnings->push_back(feature->GetErrorMessage(result));
   }
+
+  // Also generate warnings for keys that are not features.
+  for (DictionaryValue::key_iterator key = value_->begin_keys();
+      key != value_->end_keys(); ++key) {
+    if (!SimpleFeatureProvider::GetManifestFeatures()->GetFeature(*key)) {
+      warnings->push_back(base::StringPrintf("Unrecognized manifest key '%s'.",
+          (*key).c_str()));
+    }
+  }
 }
 
 bool Manifest::HasKey(const std::string& key) const {
   return CanAccessKey(key) && value_->HasKey(key);
 }
 
 bool Manifest::Get(
     const std::string& path, Value** out_value) const {
   return CanAccessPath(path) && value_->Get(path, out_value);
 }
@@ skipping 63 matching lines @@
       SimpleFeatureProvider::GetManifestFeatures()->GetFeature(key);
   if (!feature)
     return true;
 
   return Feature::IS_AVAILABLE == feature->IsAvailableToManifest(
       extension_id_, type_, Feature::ConvertLocation(location_),
       GetManifestVersion());
 }
 
 }  // namespace extensions