Implement API features for the Extension API feature system

chrome/common/extensions/features/api_feature.cc

Index: chrome/common/extensions/features/api_feature.cc
diff --git a/chrome/common/extensions/features/api_feature.cc b/chrome/common/extensions/features/api_feature.cc
new file mode 100644
index 0000000000000000000000000000000000000000..09b8c1923916813aca232fdc58e121ea0a31c308
--- /dev/null
+++ b/chrome/common/extensions/features/api_feature.cc
@@ -0,0 +1,26 @@
+// 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/features/api_feature.h"
+
+namespace extensions {
+
+APIFeature::APIFeature() {
+}
+
+APIFeature::~APIFeature() {
+}
+
+std::string APIFeature::Parse(const DictionaryValue* value) {
+  std::string error = SimpleFeature::Parse(value);
+  if (!error.empty())
+    return error;
+
+  if (GetContexts()->empty())
+    return name() + ": API features must specify at least one context.";
+
+  return "";
+}
+
+}  // namespace