Skeleton for app_list on OSX, and refactoring for enable_app_list=1 on OS=="mac".

chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm

Index: chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm b/chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm
new file mode 100644
index 0000000000000000000000000000000000000000..6f72d3171f8eaaa55b311bee5372a97ba0d31b2d
--- /dev/null
+++ b/chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm
@@ -0,0 +1,118 @@
+// Copyright 2013 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 "base/bind.h"
+#include "base/lazy_instance.h"
+#include "base/message_loop.h"
+#include "base/time.h"
+#include "base/timer.h"
+#include "chrome/browser/ui/app_list/app_list_controller.h"
+#include "ui/app_list/cocoa/app_list_view.h"
+
+namespace {
+
+class AppListControllerDelegateCocoa : public AppListControllerDelegate {
+ public:
+  AppListControllerDelegateCocoa();
+  virtual ~AppListControllerDelegateCocoa();
+
+ private:
+  // AppListControllerDelegate overrides:
+  virtual void DismissView() OVERRIDE;
+  virtual bool CanShowCreateShortcutsDialog() OVERRIDE;
+  virtual void ActivateApp(Profile* profile,
+                           const std::string& extension_id,
+                           int event_flags) OVERRIDE;
+  virtual void LaunchApp(Profile* profile,
+                         const std::string& extension_id,
+                         int event_flags) OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(AppListControllerDelegateCocoa);
+};
+
+// The AppListController class manages global resources needed for the app
+// list to operate, and controls when the app list is opened and closed.
+class AppListController {
+ public:
+  AppListController() : current_window_(NULL) {}

[sail, 2013/01/08 07:25:27]

for Objective-C classes you should use nil instead of NULL. (Though this can go
away entirely if you use scoped_nsobject()).

[tapted, 2013/01/09 04:29:49]

Good advice! Done (scoped_nsobject below).

+  ~AppListController() {}
+
+  void CreateAppList();
+  void ShowAppList();
+  void DismissAppList();
+ private:
+  NSWindow* current_window_;

[sail, 2013/01/08 07:25:27]

should be scoped_nsobject

[tapted, 2013/01/09 04:29:49]

Done.

+  base::OneShotTimer<AppListController> timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(AppListController);
+};
+
+base::LazyInstance<AppListController>::Leaky g_app_list_controller =
+    LAZY_INSTANCE_INITIALIZER;
+
+AppListControllerDelegateCocoa::AppListControllerDelegateCocoa() {}
+
+AppListControllerDelegateCocoa::~AppListControllerDelegateCocoa() {}
+
+void AppListControllerDelegateCocoa::DismissView() {
+  g_app_list_controller.Get().DismissAppList();
+}
+
+bool AppListControllerDelegateCocoa::CanShowCreateShortcutsDialog() {
+  return false;
+}
+
+void AppListControllerDelegateCocoa::ActivateApp(
+    Profile* profile, const std::string& extension_id, int event_flags) {
+  // TODO(tapted): Refactor this from Win into shared.
+}
+
+void AppListControllerDelegateCocoa::LaunchApp(
+    Profile* profile, const std::string& extension_id, int event_flags) {
+  // TODO(tapted): Refactor this from Win into shared.
+}
+
+void AppListController::CreateAppList() {
+  current_window_ = [[AppListView alloc] initAsBubble];

[sail, 2013/01/08 07:25:27]

Should also call setReleasedWhenClosed:NO
This allows you to be clear about when the reference to the window is valid.

[tapted, 2013/01/09 04:29:49]

Done (in initAsBubble).

+}
+
+void AppListController::ShowAppList() {
+  const int kLifetimeIntervalMS = 1000;
+
+  if (!current_window_)
+    CreateAppList();
+
+  timer_.Start(FROM_HERE,
+               base::TimeDelta::FromMilliseconds(kLifetimeIntervalMS), this,
+               &AppListController::DismissAppList);
+  [current_window_ makeKeyAndOrderFront:NSApp];

[sail, 2013/01/08 07:25:27]

you can just use nil instead of NSApp

[tapted, 2013/01/09 04:29:49]

Done.

+}
+
+void AppListController::DismissAppList() {
+  if (!current_window_)
+    return;
+
+  timer_.Stop();
+  [current_window_ close];

[xiyuan, 2013/01/08 17:09:37]

Reset |current_window_| to nil after closing?

[tapted, 2013/01/09 04:29:49]

I think with setReleasedWhenClosed:NO it can stick around so we can re-show it
like we do in app_list_controller_win.cc (but you're right that before I had
that change I should have been setting it to nil here). I've discovered that
"close" on Cocoa can be both "hide" and "close" in views-terminology.

+}
+
+void CreateAppList() {
+  g_app_list_controller.Get().CreateAppList();
+}
+
+}  // namespace
+
+
+namespace app_list_controller {
+
+void InitAppList() {
+  // TODO(tapted): AppList warmup code coes here.
+}
+
+void ShowAppList() {
+  // Create the App list.
+  g_app_list_controller.Get().ShowAppList();
+}
+
+}  // namespace app_list_controller