mash: Fix ash_sysui crash on startup due to missing AppListShower

ash/mus/shell_delegate_mus.cc

 // Copyright 2016 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 "ash/mus/shell_delegate_mus.h"
 
 #include "ash/default_accessibility_delegate.h"
 #include "ash/default_user_wallpaper_delegate.h"
 #include "ash/gpu_support_stub.h"
 #include "ash/media_delegate.h"
 #include "ash/mus/context_menu_mus.h"
 #include "ash/mus/shelf_delegate_mus.h"
 #include "ash/session/session_state_delegate.h"
 #include "ash/system/tray/default_system_tray_delegate.h"
 #include "base/strings/string16.h"
 #include "components/user_manager/user_info_impl.h"
+#include "ui/app_list/shower/app_list_shower.h"
 #include "ui/gfx/image/image.h"
 
 namespace ash {
 namespace sysui {
 
 namespace {
 
 class SessionStateDelegateStub : public SessionStateDelegate {
  public:
   SessionStateDelegateStub()
@@ skipping 59 matching lines @@
   void HandleMediaPrevTrack() override { NOTIMPLEMENTED(); }
   MediaCaptureState GetMediaCaptureState(UserIndex index) override {
     NOTIMPLEMENTED();
     return MEDIA_CAPTURE_NONE;
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MediaDelegateStub);
 };
 
+class AppListShowerStub : public app_list::AppListShower {

[msw, 2016/04/11 17:07:43]

nit: AppListShowerMus? It's readily discernable that these are stubs.

[James Cook, 2016/04/11 17:13:39]

Done.

+ public:
+  AppListShowerStub() {}
+  ~AppListShowerStub() override {}
+
+  // app_list::AppListShower:
+  void Show(aura::Window* window) override { NOTIMPLEMENTED(); }
+  void Dismiss() override { NOTIMPLEMENTED(); }
+  bool IsVisible() const override {
+    NOTIMPLEMENTED();
+    return false;
+  }
+  bool GetTargetVisibility() const override {
+    NOTIMPLEMENTED();
+    return false;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(AppListShowerStub);
+};
+
 }  // namespace
 
-ShellDelegateMus::ShellDelegateMus() {}
+ShellDelegateMus::ShellDelegateMus()
+    : app_list_shower_(new AppListShowerStub) {}
 
 ShellDelegateMus::~ShellDelegateMus() {}
 
 bool ShellDelegateMus::IsFirstRunAfterBoot() const {
   NOTIMPLEMENTED();
   return false;
 }
 
 bool ShellDelegateMus::IsIncognitoAllowed() const {
   NOTIMPLEMENTED();
@@ skipping 49 matching lines @@
 void ShellDelegateMus::RemoveVirtualKeyboardStateObserver(
     VirtualKeyboardStateObserver* observer) {
   NOTIMPLEMENTED();
 }
 
 void ShellDelegateMus::OpenUrl(const GURL& url) {
   NOTIMPLEMENTED();
 }
 
 app_list::AppListShower* ShellDelegateMus::GetAppListShower() {
-  NOTIMPLEMENTED();
-  return nullptr;
+  // Individual methods are marked NOTIMPLEMENTED.

[msw, 2016/04/11 17:07:43]

nit: eh, comment not worthwhile?

[James Cook, 2016/04/11 17:13:39]

Done.

+  return app_list_shower_.get();
 }
 
 ShelfDelegate* ShellDelegateMus::CreateShelfDelegate(ShelfModel* model) {
   return new ShelfDelegateMus(model);
 }
 
 SystemTrayDelegate* ShellDelegateMus::CreateSystemTrayDelegate() {
   NOTIMPLEMENTED() << " Using the default SystemTrayDelegate implementation";
   return new DefaultSystemTrayDelegate;
 }
@@ skipping 38 matching lines @@
   return base::string16();
 }
 
 gfx::Image ShellDelegateMus::GetDeprecatedAcceleratorImage() const {
   NOTIMPLEMENTED();
   return gfx::Image();
 }
 
 }  // namespace sysui
 }  // namespace ash