Create a mechanism define declarative rules via the extension manifest.

extensions/common/api/declarative/declarative_manifest_handler.cc

Index: extensions/common/api/declarative/declarative_manifest_handler.cc
diff --git a/extensions/common/api/declarative/declarative_manifest_handler.cc b/extensions/common/api/declarative/declarative_manifest_handler.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b96ddf68ad60358aa932f0046477a37d2010955b
--- /dev/null
+++ b/extensions/common/api/declarative/declarative_manifest_handler.cc
@@ -0,0 +1,36 @@
+// Copyright 2015 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 "extensions/common/api/declarative/declarative_manifest_handler.h"
+
+#include "extensions/common/api/declarative/declarative_manifest_data.h"
+#include "extensions/common/extension.h"
+#include "extensions/common/manifest_constants.h"
+
+namespace extensions {
+
+DeclarativeManifestHandler::DeclarativeManifestHandler() {
+}
+
+DeclarativeManifestHandler::~DeclarativeManifestHandler() {
+}
+
+bool DeclarativeManifestHandler::Parse(Extension* extension,
+                                       base::string16* error) {
+  const base::Value* event_rules = NULL;
+  CHECK(extension->manifest()->Get(manifest_keys::kEventRules, &event_rules));
+  scoped_ptr<DeclarativeManifestData> data =
+      DeclarativeManifestData::FromValue(*event_rules, error);
+  if (!data)
+    return false;
+
+  extension->SetManifestData(manifest_keys::kEventRules, data.release());
+  return true;
+}
+
+const std::vector<std::string> DeclarativeManifestHandler::Keys() const {
+  return SingleKey(manifest_keys::kEventRules);
+}
+
+}  // namespace extensions