Add infrastructure for Chrome Actions

chrome/browser/ui/views/toolbar/chrome_actions_registry.cc

+// Copyright 2014 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/browser/ui/views/toolbar/chrome_actions_registry.h"
+
+#include "chrome/browser/ui/views/toolbar/toolbar_action_view_controller.h"
+#include "extensions/common/feature_switch.h"
+
+namespace {
+ChromeActionsRegistry::FactoryFunction testing_factory_function = nullptr;
+}
+
+// static
+ScopedVector<ToolbarActionViewController>
+ChromeActionsRegistry::GetChromeActions() {
+  if (testing_factory_function != nullptr)
+    return testing_factory_function();
+
+  ScopedVector<ToolbarActionViewController> chrome_actions;
+
+  // This is currently behind the extension-action-redesign flag, as it is
+  // designed for the new toolbar.
+  if (!extensions::FeatureSwitch::extension_action_redesign()->IsEnabled())
+    return chrome_actions.Pass();
+
+  // Add chrome actions here.
+  // This current design means that the ChromeActionsRegistry is aware of all
+  // chrome actions (as opposed to an interface that had, e.g.,
+  // RegisterChromeAction()). This is because the latter requires a persistent
+  // object, and because we should *not* have an excessive amount of these, as
+  // each will have an action in the toolbar (or overflow menu).
+
+  return chrome_actions.Pass();
+}
+
+// static
+void ChromeActionsRegistry::SetTestingChromeActionsFunction(
+    FactoryFunction function) {
+  testing_factory_function = function;
+}