Replace with mojo::Connector (already exists) now that Shell is gone.

Requires:
- Move AppRefCount to a different class, MessageLoopRef, which is optionally used by applications that wish to quit the current message loop started by application runner when the ref drops to zero.
- Changing the signature of Initialize() to take a Connector. This is what most of the change in this CL is.

BUG=

Review URL: https://codereview.chromium.org/1725353003

Cr-Commit-Position: refs/heads/master@{#377841}

160 files changed, 663 insertions, 709 deletions

diff --git a/ash/mus/keyboard_ui_mus.cc b/ash/mus/keyboard_ui_mus.cc
index f8a1ab7..1a16aae 100644
--- a/ash/mus/keyboard_ui_mus.cc
+++ b/ash/mus/keyboard_ui_mus.cc
@@ -7,22 +7,22 @@
 #include "ash/keyboard/keyboard_ui_observer.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace ash {
 
-KeyboardUIMus::KeyboardUIMus(mojo::Shell* mojo_shell)
+KeyboardUIMus::KeyboardUIMus(mojo::Connector* connector)
     : is_enabled_(false), observer_binding_(this) {
   // TODO(sky): should be something like mojo://keyboard, but need mapping.
-  mojo_shell->ConnectToInterface("exe://chrome", &keyboard_);
+  connector->ConnectToInterface("exe://chrome", &keyboard_);
   keyboard_->AddObserver(observer_binding_.CreateInterfacePtrAndBind());
 }
 
 KeyboardUIMus::~KeyboardUIMus() {}
 
 // static
-scoped_ptr<KeyboardUI> KeyboardUIMus::Create(mojo::Shell* mojo_shell) {
-  return make_scoped_ptr(new KeyboardUIMus(mojo_shell));
+scoped_ptr<KeyboardUI> KeyboardUIMus::Create(mojo::Connector* connector) {
+  return make_scoped_ptr(new KeyboardUIMus(connector));
 }
 
 void KeyboardUIMus::Hide() {
diff --git a/ash/mus/keyboard_ui_mus.h b/ash/mus/keyboard_ui_mus.h
index 3ebf826..c7bcb24 100644
--- a/ash/mus/keyboard_ui_mus.h
+++ b/ash/mus/keyboard_ui_mus.h
@@ -11,7 +11,7 @@
 #include "ui/keyboard/keyboard.mojom.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace ash {
@@ -19,10 +19,10 @@ namespace ash {
 class KeyboardUIMus : public KeyboardUI,
                       public keyboard::mojom::KeyboardObserver {
  public:
-  explicit KeyboardUIMus(mojo::Shell* mojo_shell);
+  explicit KeyboardUIMus(mojo::Connector* connector);
   ~KeyboardUIMus() override;
 
-  static scoped_ptr<KeyboardUI> Create(mojo::Shell* mojo_shell);
+  static scoped_ptr<KeyboardUI> Create(mojo::Connector* connector);
 
   // KeyboardUI:
   void Hide() override;
diff --git a/ash/mus/shelf_delegate_mus.cc b/ash/mus/shelf_delegate_mus.cc
index d75f85a..c405fb7 100644
--- a/ash/mus/shelf_delegate_mus.cc
+++ b/ash/mus/shelf_delegate_mus.cc
@@ -16,7 +16,7 @@
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_property.h"
 #include "mojo/common/common_type_converters.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/aura/mus/mus_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/resources/grit/ui_resources.h"
@@ -90,8 +90,9 @@ class ShelfItemDelegateMus : public ShelfItemDelegate {
 
 ShelfDelegateMus::ShelfDelegateMus(ShelfModel* model)
     : model_(model), binding_(this) {
-  mojo::Shell* shell = views::WindowManagerConnection::Get()->shell();
-  shell->ConnectToInterface("mojo:desktop_wm", &user_window_controller_);
+  mojo::Connector* connector =
+      views::WindowManagerConnection::Get()->connector();
+  connector->ConnectToInterface("mojo:desktop_wm", &user_window_controller_);
   user_window_controller_->AddUserWindowObserver(
       binding_.CreateInterfacePtrAndBind());
 }
diff --git a/ash/mus/sysui_application.cc b/ash/mus/sysui_application.cc
index 361821b..c55482a 100644
--- a/ash/mus/sysui_application.cc
+++ b/ash/mus/sysui_application.cc
@@ -174,9 +174,9 @@ class AshInit {
 
   aura::Window* root() { return ash::Shell::GetPrimaryRootWindow(); }
 
-  void Initialize(mojo::Shell* shell) {
-    aura_init_.reset(new views::AuraInit(shell, "views_mus_resources.pak"));
-    views::WindowManagerConnection::Create(shell);
+  void Initialize(mojo::Connector* connector) {
+    aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
+    views::WindowManagerConnection::Create(connector);
 
     gfx::Screen* screen = gfx::Screen::GetScreen();
     DCHECK(screen);
@@ -201,7 +201,8 @@ class AshInit {
     init_params.context_factory = new StubContextFactory;
     init_params.blocking_pool = worker_pool_.get();
     init_params.in_mus = true;
-    init_params.keyboard_factory = base::Bind(&KeyboardUIMus::Create, shell);
+    init_params.keyboard_factory =
+        base::Bind(&KeyboardUIMus::Create, connector);
     ash::Shell::CreateInstance(init_params);
     ash::Shell::GetInstance()->CreateShelf();
     ash::Shell::GetInstance()->UpdateAfterLoginStatusChange(
@@ -276,12 +277,12 @@ SysUIApplication::SysUIApplication() {}
 
 SysUIApplication::~SysUIApplication() {}
 
-void SysUIApplication::Initialize(mojo::Shell* shell,
+void SysUIApplication::Initialize(mojo::Connector* connector,
                                   const std::string& url,
                                   uint32_t id,
                                   uint32_t user_id) {
   ash_init_.reset(new AshInit());
-  ash_init_->Initialize(shell);
+  ash_init_->Initialize(connector);
 }
 
 bool SysUIApplication::AcceptConnection(mojo::Connection* connection) {
diff --git a/ash/mus/sysui_application.h b/ash/mus/sysui_application.h
index c09804e..c597651 100644
--- a/ash/mus/sysui_application.h
+++ b/ash/mus/sysui_application.h
@@ -22,7 +22,7 @@ class SysUIApplication : public mojo::ShellClient {
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell,
+  void Initialize(mojo::Connector* connector,
                   const std::string& url,
                   uint32_t id,
                   uint32_t user_id) override;
diff --git a/chrome/app/mash/mash_runner.cc b/chrome/app/mash/mash_runner.cc
index c8804d3..3dc916d 100644
--- a/chrome/app/mash/mash_runner.cc
+++ b/chrome/app/mash/mash_runner.cc
@@ -24,6 +24,7 @@
 #include "mojo/shell/background/background_shell.h"
 #include "mojo/shell/identity.h"
 #include "mojo/shell/native_runner_delegate.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/cpp/shell_connection.h"
 #include "mojo/shell/public/interfaces/shell_client_factory.mojom.h"
@@ -190,8 +191,7 @@ void MashRunner::RunMain() {
       shell_client_.get(),
       background_shell.CreateShellClientRequest(GURL("exe:chrome_mash"))));
   shell_connection_->WaitForInitialize();
-  static_cast<mojo::Shell*>(shell_connection_.get())
-      ->Connect("mojo:mash_shell");
+  shell_connection_->connector()->Connect("mojo:mash_shell");
   base::MessageLoop::current()->Run();
 }
 
diff --git a/chrome/browser/ui/views/frame/browser_frame_mus.cc b/chrome/browser/ui/views/frame/browser_frame_mus.cc
index 8975f16..e0b2030 100644
--- a/chrome/browser/ui/views/frame/browser_frame_mus.cc
+++ b/chrome/browser/ui/views/frame/browser_frame_mus.cc
@@ -35,7 +35,7 @@ BrowserFrameMus::BrowserFrameMus(BrowserFrame* browser_frame,
                                  BrowserView* browser_view)
     : views::NativeWidgetMus(
           browser_frame,
-          views::WindowManagerConnection::Get()->shell(),
+          views::WindowManagerConnection::Get()->connector(),
           CreateMusWindow(browser_view),
           mus::mojom::SurfaceType::DEFAULT),
       browser_view_(browser_view) {}
diff --git a/components/bitmap_uploader/bitmap_uploader.cc b/components/bitmap_uploader/bitmap_uploader.cc
index 8a3a80f..acca97b 100644
--- a/components/bitmap_uploader/bitmap_uploader.cc
+++ b/components/bitmap_uploader/bitmap_uploader.cc
@@ -16,7 +16,7 @@
 #include "mojo/converters/surfaces/surfaces_utils.h"
 #include "mojo/public/c/gles2/chromium_extension.h"
 #include "mojo/public/c/gles2/gles2.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace bitmap_uploader {
 namespace {
@@ -46,11 +46,11 @@ BitmapUploader::~BitmapUploader() {
   MojoGLES2DestroyContext(gles2_context_);
 }
 
-void BitmapUploader::Init(mojo::Shell* shell) {
+void BitmapUploader::Init(mojo::Connector* connector) {
   surface_ = window_->RequestSurface(mus::mojom::SurfaceType::DEFAULT);
   surface_->BindToThread();
 
-  shell->ConnectToInterface("mojo:mus", &gpu_service_);
+  connector->ConnectToInterface("mojo:mus", &gpu_service_);
   mus::mojom::CommandBufferPtr gles2_client;
   gpu_service_->CreateOffscreenGLES2Context(GetProxy(&gles2_client));
   gles2_context_ = MojoGLES2CreateContext(
diff --git a/components/bitmap_uploader/bitmap_uploader.h b/components/bitmap_uploader/bitmap_uploader.h
index cee37d6..65162ac 100644
--- a/components/bitmap_uploader/bitmap_uploader.h
+++ b/components/bitmap_uploader/bitmap_uploader.h
@@ -19,7 +19,7 @@
 #include "mojo/public/c/gles2/gles2.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace bitmap_uploader {
@@ -34,7 +34,7 @@ class BITMAP_UPLOADER_EXPORT BitmapUploader
   explicit BitmapUploader(mus::Window* window);
   ~BitmapUploader() override;
 
-  void Init(mojo::Shell* shell);
+  void Init(mojo::Connector* connector);
 
   // Sets the color which is RGBA.
   void SetColor(uint32_t color);
diff --git a/components/filesystem/file_system_app.cc b/components/filesystem/file_system_app.cc
index 0de2211..8bb5354 100644
--- a/components/filesystem/file_system_app.cc
+++ b/components/filesystem/file_system_app.cc
@@ -8,7 +8,7 @@
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 #if defined(OS_WIN)
 #include "base/base_paths_win.h"
@@ -33,15 +33,14 @@ const char kUserDataDir[] = "user-data-dir";
 
 }  // namespace filesystem
 
-FileSystemApp::FileSystemApp()
-    : shell_(nullptr), lock_table_(new LockTable) {}
+FileSystemApp::FileSystemApp() : lock_table_(new LockTable) {}
 
 FileSystemApp::~FileSystemApp() {}
 
-void FileSystemApp::Initialize(mojo::Shell* shell, const std::string& url,
+void FileSystemApp::Initialize(mojo::Connector* connector,
+                               const std::string& url,
                                uint32_t id, uint32_t user_id) {
-  shell_ = shell;
-  tracing_.Initialize(shell, url);
+  tracing_.Initialize(connector, url);
 }
 
 bool FileSystemApp::AcceptConnection(mojo::Connection* connection) {
diff --git a/components/filesystem/file_system_app.h b/components/filesystem/file_system_app.h
index 3279415..f71eae9 100644
--- a/components/filesystem/file_system_app.h
+++ b/components/filesystem/file_system_app.h
@@ -15,7 +15,7 @@
 #include "mojo/shell/public/cpp/shell_client.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace filesystem {
@@ -31,7 +31,7 @@ class FileSystemApp : public mojo::ShellClient,
   static base::FilePath GetUserDataDir();
 
   // |mojo::ShellClient| override:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
@@ -39,7 +39,6 @@ class FileSystemApp : public mojo::ShellClient,
   void Create(mojo::Connection* connection,
               mojo::InterfaceRequest<FileSystem> request) override;
 
-  mojo::Shell* shell_;
   mojo::TracingImpl tracing_;
 
   scoped_ptr<LockTable> lock_table_;
diff --git a/components/filesystem/files_test_base.cc b/components/filesystem/files_test_base.cc
index d47be02..15399c3 100644
--- a/components/filesystem/files_test_base.cc
+++ b/components/filesystem/files_test_base.cc
@@ -8,7 +8,7 @@
 
 #include "components/filesystem/public/interfaces/directory.mojom.h"
 #include "components/filesystem/public/interfaces/types.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/util/capture_util.h"
 
 namespace filesystem {
@@ -21,7 +21,7 @@ FilesTestBase::~FilesTestBase() {
 
 void FilesTestBase::SetUp() {
   ApplicationTestBase::SetUp();
-  shell()->ConnectToInterface("mojo:filesystem", &files_);
+  connector()->ConnectToInterface("mojo:filesystem", &files_);
 }
 
 void FilesTestBase::GetTemporaryRoot(DirectoryPtr* directory) {
diff --git a/components/filesystem/public/cpp/prefs/pref_service_factory.cc b/components/filesystem/public/cpp/prefs/pref_service_factory.cc
index 5c75bb6..add4532 100644
--- a/components/filesystem/public/cpp/prefs/pref_service_factory.cc
+++ b/components/filesystem/public/cpp/prefs/pref_service_factory.cc
@@ -12,7 +12,7 @@
 #include "components/prefs/pref_value_store.h"
 #include "components/prefs/value_map_pref_store.h"
 #include "components/prefs/writeable_pref_store.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace filesystem {
 
@@ -23,10 +23,10 @@ void DoNothingHandleReadError(PersistentPrefStore::PrefReadError error) {}
 
 }  // namespace
 
-scoped_ptr<PrefService> CreatePrefService(mojo::Shell* shell,
+scoped_ptr<PrefService> CreatePrefService(mojo::Connector* connector,
                                           PrefRegistry* pref_registry) {
   filesystem::FileSystemPtr filesystem;
-  shell->ConnectToInterface("mojo:filesystem", &filesystem);
+  connector->ConnectToInterface("mojo:filesystem", &filesystem);
 
   scoped_refptr<FilesystemJsonPrefStore> user_prefs =
       new FilesystemJsonPrefStore("preferences.json", std::move(filesystem),
diff --git a/components/filesystem/public/cpp/prefs/pref_service_factory.h b/components/filesystem/public/cpp/prefs/pref_service_factory.h
index bff3908..23ee9ff 100644
--- a/components/filesystem/public/cpp/prefs/pref_service_factory.h
+++ b/components/filesystem/public/cpp/prefs/pref_service_factory.h
@@ -9,7 +9,7 @@
 #include "components/prefs/pref_service.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 class PrefRegistry;
@@ -19,7 +19,7 @@ namespace filesystem {
 // This factory method creates a PrefService for the local process based on the
 // preference registry passed in. This PrefService will synchronize with a JSON
 // file in the mojo:filesystem.
-scoped_ptr<PrefService> CreatePrefService(mojo::Shell* shell,
+scoped_ptr<PrefService> CreatePrefService(mojo::Connector* connector,
                                           PrefRegistry* registry);
 
 }  // namespace filesystem
diff --git a/components/font_service/font_service_app.cc b/components/font_service/font_service_app.cc
index 83cbb37..d599b09 100644
--- a/components/font_service/font_service_app.cc
+++ b/components/font_service/font_service_app.cc
@@ -58,9 +58,10 @@ FontServiceApp::FontServiceApp() {}
 
 FontServiceApp::~FontServiceApp() {}
 
-void FontServiceApp::Initialize(mojo::Shell* shell, const std::string& url,
+void FontServiceApp::Initialize(mojo::Connector* connector,
+                                const std::string& url,
                                 uint32_t id, uint32_t user_id) {
-  tracing_.Initialize(shell, url);
+  tracing_.Initialize(connector, url);
 }
 
 bool FontServiceApp::AcceptConnection(mojo::Connection* connection) {
diff --git a/components/font_service/font_service_app.h b/components/font_service/font_service_app.h
index 2963720..71d29cc 100644
--- a/components/font_service/font_service_app.h
+++ b/components/font_service/font_service_app.h
@@ -27,7 +27,7 @@ class FontServiceApp : public mojo::ShellClient,
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
diff --git a/components/font_service/public/cpp/font_loader.cc b/components/font_service/public/cpp/font_loader.cc
index 719d63d..03df30f 100644
--- a/components/font_service/public/cpp/font_loader.cc
+++ b/components/font_service/public/cpp/font_loader.cc
@@ -9,13 +9,13 @@
 #include "base/bind.h"
 #include "base/trace_event/trace_event.h"
 #include "components/font_service/public/cpp/font_service_thread.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace font_service {
 
-FontLoader::FontLoader(mojo::Shell* shell) {
+FontLoader::FontLoader(mojo::Connector* connector) {
   FontServicePtr font_service;
-  shell->ConnectToInterface("mojo:font_service", &font_service);
+  connector->ConnectToInterface("mojo:font_service", &font_service);
   thread_ = new internal::FontServiceThread(std::move(font_service));
 }
 
diff --git a/components/font_service/public/cpp/font_loader.h b/components/font_service/public/cpp/font_loader.h
index 838b8ec..557241f 100644
--- a/components/font_service/public/cpp/font_loader.h
+++ b/components/font_service/public/cpp/font_loader.h
@@ -18,7 +18,7 @@
 #include "third_party/skia/include/ports/SkFontConfigInterface.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace font_service {
@@ -35,7 +35,7 @@ class FontServiceThread;
 class FontLoader : public SkFontConfigInterface,
                    public internal::MappedFontFile::Observer {
  public:
-  explicit FontLoader(mojo::Shell* shell);
+  explicit FontLoader(mojo::Connector* connector);
   ~FontLoader() override;
 
   // Shuts down the background thread.
diff --git a/components/leveldb/leveldb_app.cc b/components/leveldb/leveldb_app.cc
index 01fd2ff..952d4f3 100644
--- a/components/leveldb/leveldb_app.cc
+++ b/components/leveldb/leveldb_app.cc
@@ -13,11 +13,11 @@ LevelDBApp::LevelDBApp() {}
 
 LevelDBApp::~LevelDBApp() {}
 
-void LevelDBApp::Initialize(mojo::Shell* shell,
+void LevelDBApp::Initialize(mojo::Connector* connector,
                             const std::string& url,
                             uint32_t id,
                             uint32_t user_id) {
-  tracing_.Initialize(shell, url);
+  tracing_.Initialize(connector, url);
   service_.reset(new LevelDBServiceImpl);
 }
 
diff --git a/components/leveldb/leveldb_app.h b/components/leveldb/leveldb_app.h
index d1cd684..d9877d9 100644
--- a/components/leveldb/leveldb_app.h
+++ b/components/leveldb/leveldb_app.h
@@ -21,7 +21,7 @@ class LevelDBApp : public mojo::ShellClient,
 
  private:
   // |ShellClient| override:
-  void Initialize(mojo::Shell* shell,
+  void Initialize(mojo::Connector* connector,
                   const std::string& url,
                   uint32_t id,
                   uint32_t user_id) override;
diff --git a/components/leveldb/leveldb_apptest.cc b/components/leveldb/leveldb_apptest.cc
index 076e9f7..2a99adc 100644
--- a/components/leveldb/leveldb_apptest.cc
+++ b/components/leveldb/leveldb_apptest.cc
@@ -28,8 +28,8 @@ class LevelDBApptest : public mojo::test::ApplicationTestBase {
   // Overridden from mojo::test::ApplicationTestBase:
   void SetUp() override {
     ApplicationTestBase::SetUp();
-    shell()->ConnectToInterface("mojo:filesystem", &files_);
-    shell()->ConnectToInterface("mojo:leveldb", &leveldb_);
+    connector()->ConnectToInterface("mojo:filesystem", &files_);
+    connector()->ConnectToInterface("mojo:leveldb", &leveldb_);
   }
 
   // Note: This has an out parameter rather than returning the |DirectoryPtr|,
diff --git a/components/mus/mus_app.cc b/components/mus/mus_app.cc
index ea2410b..3d98051 100644
--- a/components/mus/mus_app.cc
+++ b/components/mus/mus_app.cc
@@ -21,7 +21,7 @@
 #include "mojo/public/c/system/main.h"
 #include "mojo/services/tracing/public/cpp/tracing_impl.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
 #include "ui/events/event_switches.h"
@@ -58,7 +58,7 @@ struct MandolineUIServicesApp::PendingRequest {
 };
 
 MandolineUIServicesApp::MandolineUIServicesApp()
-    : shell_(nullptr) {}
+    : connector_(nullptr) {}
 
 MandolineUIServicesApp::~MandolineUIServicesApp() {
   if (gpu_state_)
@@ -67,7 +67,7 @@ MandolineUIServicesApp::~MandolineUIServicesApp() {
   connection_manager_.reset();
 }
 
-void MandolineUIServicesApp::InitializeResources(mojo::Shell* shell) {
+void MandolineUIServicesApp::InitializeResources(mojo::Connector* connector) {
   if (ui::ResourceBundle::HasSharedInstance())
     return;
 
@@ -76,7 +76,7 @@ void MandolineUIServicesApp::InitializeResources(mojo::Shell* shell) {
   resource_paths.insert(kResourceFile100);
   resource_paths.insert(kResourceFile200);
 
-  resource_provider::ResourceLoader resource_loader(shell, resource_paths);
+  resource_provider::ResourceLoader resource_loader(connector, resource_paths);
   if (!resource_loader.BlockUntilLoaded())
     return;
   CHECK(resource_loader.loaded());
@@ -92,11 +92,11 @@ void MandolineUIServicesApp::InitializeResources(mojo::Shell* shell) {
       resource_loader.ReleaseFile(kResourceFile200), ui::SCALE_FACTOR_200P);
 }
 
-void MandolineUIServicesApp::Initialize(mojo::Shell* shell,
+void MandolineUIServicesApp::Initialize(mojo::Connector* connector,
                                         const std::string& url,
                                         uint32_t id,
                                         uint32_t user_id) {
-  shell_ = shell;
+  connector_ = connector;
   surfaces_state_ = new SurfacesState;
 
   base::PlatformThread::SetName("mus");
@@ -109,7 +109,7 @@ void MandolineUIServicesApp::Initialize(mojo::Shell* shell,
   }
 #endif
 
-  InitializeResources(shell);
+  InitializeResources(connector);
 
 #if defined(USE_OZONE)
   // The ozone platform can provide its own event source. So initialize the
@@ -132,7 +132,7 @@ void MandolineUIServicesApp::Initialize(mojo::Shell* shell,
   gpu_state_ = new GpuState();
   connection_manager_.reset(new ws::ConnectionManager(this, surfaces_state_));
 
-  tracing_.Initialize(shell, url);
+  tracing_.Initialize(connector, url);
 }
 
 bool MandolineUIServicesApp::AcceptConnection(Connection* connection) {
@@ -156,7 +156,7 @@ void MandolineUIServicesApp::OnFirstRootConnectionCreated() {
 }
 
 void MandolineUIServicesApp::OnNoMoreRootConnections() {
-  shell_->Quit();
+  base::MessageLoop::current()->QuitWhenIdle();
 }
 
 ws::ClientConnection*
@@ -230,7 +230,7 @@ void MandolineUIServicesApp::CreateWindowTreeHost(
   // TODO(fsamuel): We need to make sure that only the window manager can create
   // new roots.
   ws::WindowTreeHostImpl* host_impl = new ws::WindowTreeHostImpl(
-      connection_manager_.get(), shell_, gpu_state_, surfaces_state_);
+      connection_manager_.get(), connector_, gpu_state_, surfaces_state_);
 
   // WindowTreeHostConnection manages its own lifetime.
   host_impl->Init(new ws::WindowTreeHostConnectionImpl(
diff --git a/components/mus/mus_app.h b/components/mus/mus_app.h
index 5a349c5..5c80f47 100644
--- a/components/mus/mus_app.h
+++ b/components/mus/mus_app.h
@@ -24,7 +24,7 @@
 #include "mojo/shell/public/cpp/shell_client.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace ui {
@@ -60,10 +60,10 @@ class MandolineUIServicesApp
   // has been established.
   struct PendingRequest;
 
-  void InitializeResources(mojo::Shell* shell);
+  void InitializeResources(mojo::Connector* connector);
 
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
@@ -105,7 +105,7 @@ class MandolineUIServicesApp
                             mojom::WindowTreeClientPtr tree_client) override;
 
   mojo::BindingSet<mojom::WindowTreeHostFactory> factory_bindings_;
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   scoped_ptr<ws::ConnectionManager> connection_manager_;
   scoped_refptr<GpuState> gpu_state_;
   scoped_ptr<ui::PlatformEventSource> event_source_;
diff --git a/components/mus/public/cpp/lib/window_tree_client_impl.cc b/components/mus/public/cpp/lib/window_tree_client_impl.cc
index b1107af..cdcd7b6 100644
--- a/components/mus/public/cpp/lib/window_tree_client_impl.cc
+++ b/components/mus/public/cpp/lib/window_tree_client_impl.cc
@@ -19,7 +19,7 @@
 #include "components/mus/public/cpp/window_tree_connection_observer.h"
 #include "components/mus/public/cpp/window_tree_delegate.h"
 #include "mojo/converters/geometry/geometry_type_converters.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/size.h"
 
@@ -80,10 +80,10 @@ Window* BuildWindowTree(WindowTreeClientImpl* client,
 }
 
 WindowTreeConnection* WindowTreeConnection::Create(WindowTreeDelegate* delegate,
-                                                   mojo::Shell* shell) {
+                                                   mojo::Connector* connector) {
   WindowTreeClientImpl* client =
       new WindowTreeClientImpl(delegate, nullptr, nullptr);
-  client->ConnectViaWindowTreeFactory(shell);
+  client->ConnectViaWindowTreeFactory(connector);
   return client;
 }
 
@@ -159,7 +159,7 @@ WindowTreeClientImpl::~WindowTreeClientImpl() {
 }
 
 void WindowTreeClientImpl::ConnectViaWindowTreeFactory(
-    mojo::Shell* shell) {
+    mojo::Connector* connector) {
   // Clients created with no root shouldn't delete automatically.
   delete_on_no_roots_ = false;
 
@@ -167,7 +167,7 @@ void WindowTreeClientImpl::ConnectViaWindowTreeFactory(
   connection_id_ = 101;
 
   mojom::WindowTreeFactoryPtr factory;
-  shell->ConnectToInterface("mojo:mus", &factory);
+  connector->ConnectToInterface("mojo:mus", &factory);
   factory->CreateWindowTree(GetProxy(&tree_ptr_),
                             binding_.CreateInterfacePtrAndBind());
   tree_ = tree_ptr_.get();
diff --git a/components/mus/public/cpp/lib/window_tree_client_impl.h b/components/mus/public/cpp/lib/window_tree_client_impl.h
index 991473b..9d75fa7 100644
--- a/components/mus/public/cpp/lib/window_tree_client_impl.h
+++ b/components/mus/public/cpp/lib/window_tree_client_impl.h
@@ -45,7 +45,7 @@ class WindowTreeClientImpl : public WindowTreeConnection,
   ~WindowTreeClientImpl() override;
 
   // Establishes the connection by way of the WindowTreeFactory.
-  void ConnectViaWindowTreeFactory(mojo::Shell* shell);
+  void ConnectViaWindowTreeFactory(mojo::Connector* connector);
 
   // Wait for OnEmbed(), returning when done.
   void WaitForEmbed();
diff --git a/components/mus/public/cpp/lib/window_tree_host_factory.cc b/components/mus/public/cpp/lib/window_tree_host_factory.cc
index 88c45d7..54e4d3c 100644
--- a/components/mus/public/cpp/lib/window_tree_host_factory.cc
+++ b/components/mus/public/cpp/lib/window_tree_host_factory.cc
@@ -6,7 +6,7 @@
 
 #include "components/mus/public/cpp/window_tree_connection.h"
 #include "components/mus/public/cpp/window_tree_delegate.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace mus {
 
@@ -22,12 +22,12 @@ void CreateWindowTreeHost(mojom::WindowTreeHostFactory* factory,
   factory->CreateWindowTreeHost(GetProxy(host), std::move(tree_client));
 }
 
-void CreateWindowTreeHost(mojo::Shell* shell,
+void CreateWindowTreeHost(mojo::Connector* connector,
                           WindowTreeDelegate* delegate,
                           mojom::WindowTreeHostPtr* host,
                           WindowManagerDelegate* window_manager_delegate) {
   mojom::WindowTreeHostFactoryPtr factory;
-  shell->ConnectToInterface("mojo:mus", &factory);
+  connector->ConnectToInterface("mojo:mus", &factory);
   CreateWindowTreeHost(factory.get(), delegate, host, window_manager_delegate);
 }
 
diff --git a/components/mus/public/cpp/tests/window_server_test_base.cc b/components/mus/public/cpp/tests/window_server_test_base.cc
index ab47629..affbf31 100644
--- a/components/mus/public/cpp/tests/window_server_test_base.cc
+++ b/components/mus/public/cpp/tests/window_server_test_base.cc
@@ -11,7 +11,7 @@
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_tree_connection.h"
 #include "components/mus/public/cpp/window_tree_host_factory.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace mus {
 namespace {
@@ -65,7 +65,7 @@ bool WindowServerTestBase::QuitRunLoop() {
 void WindowServerTestBase::SetUp() {
   ApplicationTestBase::SetUp();
 
-  CreateWindowTreeHost(shell(), this, &host_, this);
+  CreateWindowTreeHost(connector(), this, &host_, this);
 
   ASSERT_TRUE(DoRunLoopWithTimeout());  // RunLoop should be quit by OnEmbed().
   std::swap(window_manager_, most_recent_connection_);
diff --git a/components/mus/public/cpp/window_tree_connection.h b/components/mus/public/cpp/window_tree_connection.h
index 31528ac..d99eda2 100644
--- a/components/mus/public/cpp/window_tree_connection.h
+++ b/components/mus/public/cpp/window_tree_connection.h
@@ -16,7 +16,7 @@
 #include "mojo/public/cpp/bindings/interface_request.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -43,7 +43,7 @@ class WindowTreeConnection {
   // Creates a WindowTreeConnection with no roots. Use this to establish a
   // connection directly to mus and create top level windows.
   static WindowTreeConnection* Create(WindowTreeDelegate* delegate,
-                                      mojo::Shell* shell);
+                                      mojo::Connector* connector);
 
   // Creates a WindowTreeConnection to service the specified request for
   // a WindowTreeClient. Use this to be embedded in another app.
diff --git a/components/mus/public/cpp/window_tree_host_factory.h b/components/mus/public/cpp/window_tree_host_factory.h
index 1c75de8..b3a5bab 100644
--- a/components/mus/public/cpp/window_tree_host_factory.h
+++ b/components/mus/public/cpp/window_tree_host_factory.h
@@ -11,7 +11,7 @@
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -26,7 +26,7 @@ void CreateWindowTreeHost(mojom::WindowTreeHostFactory* factory,
                           WindowTreeDelegate* delegate,
                           mojom::WindowTreeHostPtr* host,
                           WindowManagerDelegate* window_manager_delegate);
-void CreateWindowTreeHost(mojo::Shell* shell,
+void CreateWindowTreeHost(mojo::Connector* connector,
                           WindowTreeDelegate* delegate,
                           mojom::WindowTreeHostPtr* host,
                           WindowManagerDelegate* window_manager_delegate);
diff --git a/components/mus/ws/display_manager.cc b/components/mus/ws/display_manager.cc
index a35e08b..8b991f8 100644
--- a/components/mus/ws/display_manager.cc
+++ b/components/mus/ws/display_manager.cc
@@ -29,7 +29,7 @@
 #include "mojo/converters/surfaces/surfaces_utils.h"
 #include "mojo/converters/transform/transform_type_converters.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/base/cursor/cursor_loader.h"
 #include "ui/events/event.h"
@@ -155,19 +155,19 @@ DisplayManagerFactory* DisplayManager::factory_ = nullptr;
 
 // static
 DisplayManager* DisplayManager::Create(
-    mojo::Shell* shell,
+    mojo::Connector* connector,
     const scoped_refptr<GpuState>& gpu_state,
     const scoped_refptr<SurfacesState>& surfaces_state) {
   if (factory_)
-    return factory_->CreateDisplayManager(shell, gpu_state, surfaces_state);
-  return new DefaultDisplayManager(shell, gpu_state, surfaces_state);
+    return factory_->CreateDisplayManager(connector, gpu_state, surfaces_state);
+  return new DefaultDisplayManager(connector, gpu_state, surfaces_state);
 }
 
 DefaultDisplayManager::DefaultDisplayManager(
-    mojo::Shell* shell,
+    mojo::Connector* connector,
     const scoped_refptr<GpuState>& gpu_state,
     const scoped_refptr<SurfacesState>& surfaces_state)
-    : shell_(shell),
+    : connector_(connector),
       gpu_state_(gpu_state),
       surfaces_state_(surfaces_state),
       delegate_(nullptr),
diff --git a/components/mus/ws/display_manager.h b/components/mus/ws/display_manager.h
index 49a1f92..ce93485 100644
--- a/components/mus/ws/display_manager.h
+++ b/components/mus/ws/display_manager.h
@@ -35,7 +35,7 @@ class GpuState;
 }  // namespace gles2
 
 namespace mojo {
-class Shell;
+class Connector;
 }  // namespace mojo
 
 namespace ui {
@@ -63,7 +63,7 @@ class DisplayManager {
   virtual ~DisplayManager() {}
 
   static DisplayManager* Create(
-      mojo::Shell* shell,
+      mojo::Connector* connector,
       const scoped_refptr<GpuState>& gpu_state,
       const scoped_refptr<SurfacesState>& surfaces_state);
 
@@ -112,7 +112,7 @@ class DisplayManager {
 class DefaultDisplayManager : public DisplayManager,
                               public ui::PlatformWindowDelegate {
  public:
-  DefaultDisplayManager(mojo::Shell* shell,
+  DefaultDisplayManager(mojo::Connector* connector,
                         const scoped_refptr<GpuState>& gpu_state,
                         const scoped_refptr<SurfacesState>& surfaces_state);
   ~DefaultDisplayManager() override;
@@ -162,7 +162,7 @@ class DefaultDisplayManager : public DisplayManager,
   void OnAcceleratedWidgetDestroyed() override;
   void OnActivationChanged(bool active) override;
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   scoped_refptr<GpuState> gpu_state_;
   scoped_refptr<SurfacesState> surfaces_state_;
   DisplayManagerDelegate* delegate_;
diff --git a/components/mus/ws/display_manager_factory.h b/components/mus/ws/display_manager_factory.h
index 49bc734..f73ac80 100644
--- a/components/mus/ws/display_manager_factory.h
+++ b/components/mus/ws/display_manager_factory.h
@@ -9,7 +9,7 @@
 #include "mojo/public/cpp/bindings/callback.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -23,7 +23,7 @@ class DisplayManager;
 class DisplayManagerFactory {
  public:
   virtual DisplayManager* CreateDisplayManager(
-      mojo::Shell* shell,
+      mojo::Connector* connector,
       const scoped_refptr<mus::GpuState>& gpu_state,
       const scoped_refptr<mus::SurfacesState>& surfaces_state) = 0;
 };
diff --git a/components/mus/ws/window_manager_client_apptest.cc b/components/mus/ws/window_manager_client_apptest.cc
index 5d9f111..8bc7972 100644
--- a/components/mus/ws/window_manager_client_apptest.cc
+++ b/components/mus/ws/window_manager_client_apptest.cc
@@ -275,7 +275,7 @@ class WindowServerTest : public WindowServerTestBase {
   // WindowTreeClient.
   mus::mojom::WindowTreeClientPtr ConnectAndGetWindowServerClient() {
     mus::mojom::WindowTreeClientPtr client;
-    shell()->ConnectToInterface(shell_url(), &client);
+    connector()->ConnectToInterface(test_url(), &client);
     return client;
   }
 
@@ -1159,7 +1159,7 @@ TEST_F(WindowServerTest, EstablishConnectionViaFactory) {
   EstablishConnectionViaFactoryDelegate delegate(window_manager());
   set_window_manager_delegate(&delegate);
   scoped_ptr<WindowTreeConnection> second_connection(
-      WindowTreeConnection::Create(this, shell()));
+      WindowTreeConnection::Create(this, connector()));
   Window* window_in_second_connection =
       second_connection->NewTopLevelWindow(nullptr);
   ASSERT_TRUE(window_in_second_connection);
diff --git a/components/mus/ws/window_tree_apptest.cc b/components/mus/ws/window_tree_apptest.cc
index ee2a186..cc18e0d 100644
--- a/components/mus/ws/window_tree_apptest.cc
+++ b/components/mus/ws/window_tree_apptest.cc
@@ -63,7 +63,7 @@ void EmbedCallbackImpl(base::RunLoop* run_loop,
 
 // -----------------------------------------------------------------------------
 
-bool EmbedUrl(mojo::Shell* shell,
+bool EmbedUrl(mojo::Connector* connector,
               WindowTree* ws,
               const String& url,
               Id root_id) {
@@ -71,7 +71,7 @@ bool EmbedUrl(mojo::Shell* shell,
   base::RunLoop run_loop;
   {
     mojom::WindowTreeClientPtr client;
-    shell->ConnectToInterface(url.get(), &client);
+    connector->ConnectToInterface(url.get(), &client);
     ws->Embed(root_id, std::move(client),
               mojom::WindowTree::kAccessPolicyDefault,
               base::Bind(&EmbedCallbackImpl, &run_loop, &result));
@@ -547,7 +547,7 @@ class WindowTreeAppTest : public mojo::test::ApplicationTestBase,
                                                Id root_id,
                                                uint32_t policy_bitmask,
                                                int* connection_id) {
-    if (!EmbedUrl(shell(), owner, shell_url(), root_id)) {
+    if (!EmbedUrl(connector(), owner, test_url(), root_id)) {
       ADD_FAILURE() << "Embed() failed";
       return nullptr;
     }
@@ -573,7 +573,7 @@ class WindowTreeAppTest : public mojo::test::ApplicationTestBase,
     client_factory_.reset(new WindowTreeClientFactory());
 
     mojom::WindowTreeHostFactoryPtr factory;
-    shell()->ConnectToInterface("mojo:mus", &factory);
+    connector()->ConnectToInterface("mojo:mus", &factory);
 
     mojom::WindowTreeClientPtr tree_client_ptr;
     ws_client1_.reset(new TestWindowTreeClientImpl());
@@ -1724,7 +1724,7 @@ TEST_F(WindowTreeAppTest, EmbedFailsFromOtherConnection) {
   // 2 should not be able to embed in window_3_3 as window_3_3 was not created
   // by
   // 2.
-  EXPECT_FALSE(EmbedUrl(shell(), ws2(), shell_url(), window_3_3));
+  EXPECT_FALSE(EmbedUrl(connector(), ws2(), test_url(), window_3_3));
 }
 
 // Verifies Embed() from window manager on another connections window works.
@@ -1747,7 +1747,7 @@ TEST_F(WindowTreeAppTest, EmbedFromOtherConnection) {
 
 TEST_F(WindowTreeAppTest, CantEmbedFromConnectionRoot) {
   // Shouldn't be able to embed into the root.
-  ASSERT_FALSE(EmbedUrl(shell(), ws1(), shell_url(), root_window_id()));
+  ASSERT_FALSE(EmbedUrl(connector(), ws1(), test_url(), root_window_id()));
 
   // Even though the call above failed a WindowTreeClient was obtained. We need
   // to
@@ -1756,7 +1756,7 @@ TEST_F(WindowTreeAppTest, CantEmbedFromConnectionRoot) {
 
   // Don't allow a connection to embed into its own root.
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(true));
-  EXPECT_FALSE(EmbedUrl(shell(), ws2(), shell_url(),
+  EXPECT_FALSE(EmbedUrl(connector(), ws2(), test_url(),
                         BuildWindowId(connection_id_1(), 1)));
 
   // Need to wait for a WindowTreeClient for same reason as above.
@@ -1773,7 +1773,7 @@ TEST_F(WindowTreeAppTest, CantEmbedFromConnectionRoot) {
 
   // window_1_2 is ws3's root, so even though v3 is an embed root it should not
   // be able to Embed into itself.
-  ASSERT_FALSE(EmbedUrl(shell(), ws3(), shell_url(), window_1_2));
+  ASSERT_FALSE(EmbedUrl(connector(), ws3(), test_url(), window_1_2));
 }
 
 // Verifies that a transient window tracks its parent's lifetime.
diff --git a/components/mus/ws/window_tree_host_impl.cc b/components/mus/ws/window_tree_host_impl.cc
index d80ef83..46f3e91 100644
--- a/components/mus/ws/window_tree_host_impl.cc
+++ b/components/mus/ws/window_tree_host_impl.cc
@@ -87,7 +87,7 @@ WindowTreeHostImpl::QueuedEvent::~QueuedEvent() {}
 
 WindowTreeHostImpl::WindowTreeHostImpl(
     ConnectionManager* connection_manager,
-    mojo::Shell* shell,
+    mojo::Connector* connector,
     const scoped_refptr<GpuState>& gpu_state,
     const scoped_refptr<SurfacesState>& surfaces_state)
     : id_(next_id++),
@@ -95,7 +95,7 @@ WindowTreeHostImpl::WindowTreeHostImpl(
       connection_manager_(connection_manager),
       event_dispatcher_(this),
       display_manager_(
-          DisplayManager::Create(shell, gpu_state, surfaces_state)),
+          DisplayManager::Create(connector, gpu_state, surfaces_state)),
       tree_awaiting_input_ack_(nullptr),
       last_cursor_(0) {
   frame_decoration_values_ = mojom::FrameDecorationValues::New();
diff --git a/components/mus/ws/window_tree_host_impl.h b/components/mus/ws/window_tree_host_impl.h
index cace4be..a1f93d1 100644
--- a/components/mus/ws/window_tree_host_impl.h
+++ b/components/mus/ws/window_tree_host_impl.h
@@ -48,7 +48,7 @@ class WindowTreeHostImpl : public DisplayManagerDelegate,
   // DisplayManagers. We should probably just store these common parameters
   // in the DisplayManagerFactory and pass them along on DisplayManager::Create.
   WindowTreeHostImpl(ConnectionManager* connection_manager,
-                     mojo::Shell* shell,
+                     mojo::Connector* connector,
                      const scoped_refptr<GpuState>& gpu_state,
                      const scoped_refptr<SurfacesState>& surfaces_state);
   ~WindowTreeHostImpl() override;
diff --git a/components/mus/ws/window_tree_unittest.cc b/components/mus/ws/window_tree_unittest.cc
index 99e53a5..bafcf2d 100644
--- a/components/mus/ws/window_tree_unittest.cc
+++ b/components/mus/ws/window_tree_unittest.cc
@@ -352,7 +352,7 @@ class TestDisplayManagerFactory : public DisplayManagerFactory {
       : cursor_id_storage_(cursor_id_storage) {}
   ~TestDisplayManagerFactory() {}
   DisplayManager* CreateDisplayManager(
-      mojo::Shell* shell,
+      mojo::Connector* connector,
       const scoped_refptr<GpuState>& gpu_state,
       const scoped_refptr<mus::SurfacesState>& surfaces_state) override {
     return new TestDisplayManager(cursor_id_storage_);
diff --git a/components/resource_provider/public/cpp/resource_loader.cc b/components/resource_provider/public/cpp/resource_loader.cc
index 1bd8b7c..fc33a36 100644
--- a/components/resource_provider/public/cpp/resource_loader.cc
+++ b/components/resource_provider/public/cpp/resource_loader.cc
@@ -11,7 +11,7 @@
 #include "base/files/file.h"
 #include "mojo/common/common_type_converters.h"
 #include "mojo/platform_handle/platform_handle_functions.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/interfaces/interface_provider.mojom.h"
 #include "mojo/shell/public/interfaces/shell.mojom.h"
 
@@ -26,10 +26,10 @@ base::File GetFileFromHandle(mojo::ScopedHandle handle) {
 }
 }
 
-ResourceLoader::ResourceLoader(mojo::Shell* shell,
+ResourceLoader::ResourceLoader(mojo::Connector* connector,
                                const std::set<std::string>& paths)
     : loaded_(false), did_block_(false) {
-  shell->ConnectToInterface("mojo:resource_provider", &resource_provider_);
+  connector->ConnectToInterface("mojo:resource_provider", &resource_provider_);
   std::vector<std::string> paths_vector(paths.begin(), paths.end());
   resource_provider_->GetResources(
       mojo::Array<mojo::String>::From(paths_vector),
diff --git a/components/resource_provider/public/cpp/resource_loader.h b/components/resource_provider/public/cpp/resource_loader.h
index e355d6e..033cfdd 100644
--- a/components/resource_provider/public/cpp/resource_loader.h
+++ b/components/resource_provider/public/cpp/resource_loader.h
@@ -22,7 +22,7 @@ class File;
 }
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace resource_provider {
@@ -33,7 +33,8 @@ namespace resource_provider {
 // have been obtained.
 class ResourceLoader {
  public:
-  ResourceLoader(mojo::Shell* shell, const std::set<std::string>& paths);
+  ResourceLoader(mojo::Connector* connector,
+                 const std::set<std::string>& paths);
   ~ResourceLoader();
 
   // Uses WaitForIncomingMessage() to block until the results are available, or
diff --git a/components/resource_provider/resource_provider_app.cc b/components/resource_provider/resource_provider_app.cc
index b3723ab..85e6e28 100644
--- a/components/resource_provider/resource_provider_app.cc
+++ b/components/resource_provider/resource_provider_app.cc
@@ -21,9 +21,10 @@ ResourceProviderApp::ResourceProviderApp(
 ResourceProviderApp::~ResourceProviderApp() {
 }
 
-void ResourceProviderApp::Initialize(mojo::Shell* shell, const std::string& url,
+void ResourceProviderApp::Initialize(mojo::Connector* connector,
+                                     const std::string& url,
                                      uint32_t id, uint32_t user_id) {
-  tracing_.Initialize(shell, url);
+  tracing_.Initialize(connector, url);
 }
 
 bool ResourceProviderApp::AcceptConnection(mojo::Connection* connection) {
diff --git a/components/resource_provider/resource_provider_app.h b/components/resource_provider/resource_provider_app.h
index 056c97f..0f2d0f0 100644
--- a/components/resource_provider/resource_provider_app.h
+++ b/components/resource_provider/resource_provider_app.h
@@ -15,10 +15,6 @@
 #include "mojo/shell/public/cpp/interface_factory.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 
-namespace mojo {
-class Shell;
-}
-
 namespace resource_provider {
 
 class ResourceProviderApp : public mojo::ShellClient,
@@ -29,7 +25,7 @@ class ResourceProviderApp : public mojo::ShellClient,
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
diff --git a/components/resource_provider/resource_provider_apptest.cc b/components/resource_provider/resource_provider_apptest.cc
index cc5bfe1..aecd282 100644
--- a/components/resource_provider/resource_provider_apptest.cc
+++ b/components/resource_provider/resource_provider_apptest.cc
@@ -55,7 +55,7 @@ class ResourceProviderApplicationTest : public mojo::test::ApplicationTestBase {
   // resources are returned. The return map maps from the path to the contents
   // of the file at the specified path.
   ResourceContentsMap GetResources(const std::set<std::string>& paths) {
-    ResourceLoader loader(shell(), paths);
+    ResourceLoader loader(connector(), paths);
     loader.BlockUntilLoaded();
 
     // Load the contents of each of the handles.
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index d7a4638..f7cfb45 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -179,6 +179,7 @@
 #endif
 
 #if defined(MOJO_SHELL_CLIENT)
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/views/mus/window_manager_connection.h"
 #endif
 
@@ -919,7 +920,7 @@ int BrowserMainLoop::PreMainMessageLoopRun() {
     MojoShellConnectionImpl::Get()->BindToCommandLinePlatformChannel();
 #if defined(MOJO_SHELL_CLIENT) && defined(USE_AURA)
     views::WindowManagerConnection::Create(
-        MojoShellConnection::Get()->GetShell());
+        MojoShellConnection::Get()->GetConnector());
 #endif
   }
 
diff --git a/content/browser/mojo/mojo_shell_client_host.cc b/content/browser/mojo/mojo_shell_client_host.cc
index 6a7b707..2cc0da6 100644
--- a/content/browser/mojo/mojo_shell_client_host.cc
+++ b/content/browser/mojo/mojo_shell_client_host.cc
@@ -21,7 +21,7 @@
 #include "mojo/edk/embedder/embedder.h"
 #include "mojo/edk/embedder/platform_channel_pair.h"
 #include "mojo/edk/embedder/scoped_platform_handle.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/interfaces/application_manager.mojom.h"
 
 namespace content {
@@ -134,7 +134,7 @@ void RegisterChildWithExternalShell(int child_process_id,
       mojo::edk::CreateMessagePipe(std::move(parent_pipe));
 
   mojo::shell::mojom::ApplicationManagerPtr application_manager;
-  MojoShellConnection::Get()->GetShell()->ConnectToInterface(
+  MojoShellConnection::Get()->GetConnector()->ConnectToInterface(
       "mojo:shell", &application_manager);
 
   // The content of the URL/qualifier we pass is actually meaningless, it's only
diff --git a/content/browser/renderer_host/render_widget_host_view_mus.cc b/content/browser/renderer_host/render_widget_host_view_mus.cc
index 4bd3d57..9ddef3e 100644
--- a/content/browser/renderer_host/render_widget_host_view_mus.cc
+++ b/content/browser/renderer_host/render_widget_host_view_mus.cc
@@ -14,7 +14,7 @@
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/common/render_widget_window_tree_client_factory.mojom.h"
 #include "content/public/common/mojo_shell_connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/window.h"
 #include "ui/base/hit_test.h"
@@ -40,7 +40,7 @@ RenderWidgetHostViewMus::RenderWidgetHostViewMus(mus::Window* parent_window,
   // and embed that client inside our mus window.
   std::string url = GetMojoApplicationInstanceURL(host_->GetProcess());
   mojom::RenderWidgetWindowTreeClientFactoryPtr factory;
-  MojoShellConnection::Get()->GetShell()->ConnectToInterface(url, &factory);
+  MojoShellConnection::Get()->GetConnector()->ConnectToInterface(url, &factory);
 
   mus::mojom::WindowTreeClientPtr window_tree_client;
   factory->CreateWindowTreeClientForRenderWidget(
diff --git a/content/common/mojo/mojo_shell_connection_impl.cc b/content/common/mojo/mojo_shell_connection_impl.cc
index 8531205..6b19b3f2 100644
--- a/content/common/mojo/mojo_shell_connection_impl.cc
+++ b/content/common/mojo/mojo_shell_connection_impl.cc
@@ -93,7 +93,7 @@ void MojoShellConnectionImpl::WaitForShell(
   shell_connection_->WaitForInitialize();
 }
 
-void MojoShellConnectionImpl::Initialize(mojo::Shell* shell,
+void MojoShellConnectionImpl::Initialize(mojo::Connector* connector,
                                          const std::string& url,
                                          uint32_t id,
                                          uint32_t user_id) {
@@ -107,9 +107,9 @@ bool MojoShellConnectionImpl::AcceptConnection(mojo::Connection* connection) {
   return found;
 }
 
-mojo::Shell* MojoShellConnectionImpl::GetShell() {
+mojo::Connector* MojoShellConnectionImpl::GetConnector() {
   DCHECK(initialized_);
-  return shell_connection_.get();
+  return shell_connection_->connector();
 }
 
 bool MojoShellConnectionImpl::UsingExternalShell() const {
diff --git a/content/common/mojo/mojo_shell_connection_impl.h b/content/common/mojo/mojo_shell_connection_impl.h
index dd588e0..73ae507 100644
--- a/content/common/mojo/mojo_shell_connection_impl.h
+++ b/content/common/mojo/mojo_shell_connection_impl.h
@@ -56,12 +56,12 @@ class MojoShellConnectionImpl : public MojoShellConnection,
   ~MojoShellConnectionImpl() override;
 
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
   // MojoShellConnection:
-  mojo::Shell* GetShell() override;
+  mojo::Connector* GetConnector() override;
   bool UsingExternalShell() const override;
   void AddListener(Listener* listener) override;
   void RemoveListener(Listener* listener) override;
diff --git a/content/public/common/mojo_shell_connection.h b/content/public/common/mojo_shell_connection.h
index 59c38b3..50827a9 100644
--- a/content/public/common/mojo_shell_connection.h
+++ b/content/public/common/mojo_shell_connection.h
@@ -9,7 +9,7 @@
 
 namespace mojo {
 class Connection;
-class Shell;
+class Connector;
 }
 
 namespace content {
@@ -41,8 +41,7 @@ class CONTENT_EXPORT MojoShellConnection {
   // created on.
   static void Destroy();
 
-  // Returns an Initialized() Shell.
-  virtual mojo::Shell* GetShell() = 0;
+  virtual mojo::Connector* GetConnector() = 0;
 
   // Indicates whether the shell connection is to an external shell (true) or
   // a shell embedded in the browser process (false).
diff --git a/content/public/test/test_mojo_app.cc b/content/public/test/test_mojo_app.cc
index cc80175..4fb1b27 100644
--- a/content/public/test/test_mojo_app.cc
+++ b/content/public/test/test_mojo_app.cc
@@ -7,24 +7,20 @@
 #include <utility>
 
 #include "base/logging.h"
+#include "base/message_loop/message_loop.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace content {
 
 const char kTestMojoAppUrl[] = "system:content_mojo_test";
 
-TestMojoApp::TestMojoApp() : service_binding_(this), shell_(nullptr) {
+TestMojoApp::TestMojoApp() : service_binding_(this) {
 }
 
 TestMojoApp::~TestMojoApp() {
 }
 
-void TestMojoApp::Initialize(mojo::Shell* shell, const std::string& url,
-                             uint32_t id, uint32_t user_id) {
-  shell_ = shell;
-}
-
 bool TestMojoApp::AcceptConnection(mojo::Connection* connection) {
   requestor_url_ = GURL(connection->GetRemoteApplicationURL());
   connection->AddInterface<TestMojoService>(this);
@@ -39,8 +35,7 @@ void TestMojoApp::Create(mojo::Connection* connection,
 
 void TestMojoApp::DoSomething(const DoSomethingCallback& callback) {
   callback.Run();
-  DCHECK(shell_);
-  shell_->Quit();
+  base::MessageLoop::current()->QuitWhenIdle();
 }
 
 void TestMojoApp::GetRequestorURL(const GetRequestorURLCallback& callback) {
diff --git a/content/public/test/test_mojo_app.h b/content/public/test/test_mojo_app.h
index edf0ad28..0ce330a 100644
--- a/content/public/test/test_mojo_app.h
+++ b/content/public/test/test_mojo_app.h
@@ -27,8 +27,6 @@ class TestMojoApp : public mojo::ShellClient,
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
-                  uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
   // mojo::InterfaceFactory<TestMojoService>:
@@ -41,9 +39,6 @@ class TestMojoApp : public mojo::ShellClient,
 
   mojo::Binding<TestMojoService> service_binding_;
 
-  // Not owned.
-  mojo::Shell* shell_;
-
   // The URL of the app connecting to us.
   GURL requestor_url_;
 
diff --git a/content/renderer/mus/render_widget_mus_connection.cc b/content/renderer/mus/render_widget_mus_connection.cc
index 3ac0808..c2dc1d1 100644
--- a/content/renderer/mus/render_widget_mus_connection.cc
+++ b/content/renderer/mus/render_widget_mus_connection.cc
@@ -20,7 +20,7 @@
 #include "content/renderer/render_view_impl.h"
 #include "mojo/converters/geometry/geometry_type_converters.h"
 #include "mojo/converters/surfaces/surfaces_utils.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace content {
 
@@ -49,8 +49,8 @@ scoped_ptr<cc::OutputSurface> RenderWidgetMusConnection::CreateOutputSurface() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!window_surface_binding_);
   mus::mojom::GpuPtr gpu_service;
-  MojoShellConnection::Get()->GetShell()->ConnectToInterface("mojo:mus",
-                                                             &gpu_service);
+  MojoShellConnection::Get()->GetConnector()->ConnectToInterface("mojo:mus",
+                                                                 &gpu_service);
   mus::mojom::CommandBufferPtr cb;
   gpu_service->CreateOffscreenGLES2Context(GetProxy(&cb));
   scoped_refptr<cc::ContextProvider> context_provider(
diff --git a/mash/browser_driver/browser_driver_application_delegate.cc b/mash/browser_driver/browser_driver_application_delegate.cc
index 674be25..e5ea59a 100644
--- a/mash/browser_driver/browser_driver_application_delegate.cc
+++ b/mash/browser_driver/browser_driver_application_delegate.cc
@@ -9,7 +9,7 @@
 #include "base/bind.h"
 #include "components/mus/public/cpp/event_matcher.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace mash {
 namespace browser_driver {
@@ -45,16 +45,16 @@ void AssertTrue(bool success) {
 }  // namespace
 
 BrowserDriverApplicationDelegate::BrowserDriverApplicationDelegate()
-    : shell_(nullptr),
+    : connector_(nullptr),
       binding_(this) {}
 
 BrowserDriverApplicationDelegate::~BrowserDriverApplicationDelegate() {}
 
-void BrowserDriverApplicationDelegate::Initialize(mojo::Shell* shell,
+void BrowserDriverApplicationDelegate::Initialize(mojo::Connector* connector,
                                                   const std::string& url,
                                                   uint32_t id,
                                                   uint32_t user_id) {
-  shell_ = shell;
+  connector_ = connector;
   AddAccelerators();
 }
 
@@ -69,7 +69,7 @@ void BrowserDriverApplicationDelegate::OnAccelerator(
     case Accelerator::NewWindow:
     case Accelerator::NewTab:
     case Accelerator::NewIncognitoWindow:
-      shell_->Connect("exe:chrome");
+      connector_->Connect("exe:chrome");
       // TODO(beng): have Chrome export a service that allows it to be driven by
       //             this driver, e.g. to open new tabs, incognito windows, etc.
       break;
@@ -83,7 +83,7 @@ void BrowserDriverApplicationDelegate::AddAccelerators() {
   // TODO(beng): find some other way to get the window manager. I don't like
   //             having to specify it by URL because it may differ per display.
   mus::mojom::AcceleratorRegistrarPtr registrar;
-  shell_->ConnectToInterface("mojo:desktop_wm", &registrar);
+  connector_->ConnectToInterface("mojo:desktop_wm", &registrar);
 
   if (binding_.is_bound())
     binding_.Unbind();
diff --git a/mash/browser_driver/browser_driver_application_delegate.h b/mash/browser_driver/browser_driver_application_delegate.h
index ff2aa9a..cbe63cf 100644
--- a/mash/browser_driver/browser_driver_application_delegate.h
+++ b/mash/browser_driver/browser_driver_application_delegate.h
@@ -27,7 +27,7 @@ class BrowserDriverApplicationDelegate : public mojo::ShellClient,
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
@@ -36,7 +36,7 @@ class BrowserDriverApplicationDelegate : public mojo::ShellClient,
 
   void AddAccelerators();
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   mojo::Binding<mus::mojom::AcceleratorHandler> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserDriverApplicationDelegate);
diff --git a/mash/example/views_examples/views_examples_application_delegate.cc b/mash/example/views_examples/views_examples_application_delegate.cc
index 9be2175..1c4c200 100644
--- a/mash/example/views_examples/views_examples_application_delegate.cc
+++ b/mash/example/views_examples/views_examples_application_delegate.cc
@@ -5,7 +5,7 @@
 #include "mash/example/views_examples/views_examples_application_delegate.h"
 
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/views/examples/example_base.h"
 #include "ui/views/examples/examples_window.h"
 #include "ui/views/mus/aura_init.h"
@@ -16,14 +16,14 @@ ViewsExamplesApplicationDelegate::ViewsExamplesApplicationDelegate() {}
 ViewsExamplesApplicationDelegate::~ViewsExamplesApplicationDelegate() {
 }
 
-void ViewsExamplesApplicationDelegate::Initialize(mojo::Shell* shell,
+void ViewsExamplesApplicationDelegate::Initialize(mojo::Connector* connector,
                                                   const std::string& url,
                                                   uint32_t id,
                                                   uint32_t user_id) {
-  tracing_.Initialize(shell, url);
-  aura_init_.reset(new views::AuraInit(shell, "views_mus_resources.pak"));
+  tracing_.Initialize(connector, url);
+  aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
 
-  views::WindowManagerConnection::Create(shell);
+  views::WindowManagerConnection::Create(connector);
 
   views::examples::ShowExamplesWindow(views::examples::DO_NOTHING_ON_CLOSE,
                                       nullptr, nullptr);
diff --git a/mash/example/views_examples/views_examples_application_delegate.h b/mash/example/views_examples/views_examples_application_delegate.h
index 90f28ce..e7d9eec 100644
--- a/mash/example/views_examples/views_examples_application_delegate.h
+++ b/mash/example/views_examples/views_examples_application_delegate.h
@@ -21,7 +21,7 @@ class ViewsExamplesApplicationDelegate : public mojo::ShellClient {
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
diff --git a/mash/example/window_type_launcher/window_type_launcher.cc b/mash/example/window_type_launcher/window_type_launcher.cc
index a5dacd0..d4fdc69 100644
--- a/mash/example/window_type_launcher/window_type_launcher.cc
+++ b/mash/example/window_type_launcher/window_type_launcher.cc
@@ -9,7 +9,7 @@
 #include "mash/shell/public/interfaces/shell.mojom.h"
 #include "mojo/converters/geometry/geometry_type_converters.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/compositor/layer.h"
@@ -164,8 +164,8 @@ class WindowTypeLauncherView : public views::WidgetDelegateView,
                                public views::MenuDelegate,
                                public views::ContextMenuController {
  public:
-  explicit WindowTypeLauncherView(mojo::Shell* shell)
-      : shell_(shell),
+  explicit WindowTypeLauncherView(mojo::Connector* connector)
+      : connector_(connector),
         create_button_(new views::LabelButton(
             this, base::ASCIIToUTF16("Create Window"))),
         panel_button_(new views::LabelButton(
@@ -274,7 +274,7 @@ class WindowTypeLauncherView : public views::WidgetDelegateView,
     }
     else if (sender == lock_button_) {
       mash::shell::mojom::ShellPtr shell;
-      shell_->ConnectToInterface("mojo:mash_shell", &shell);
+      connector_->ConnectToInterface("mojo:mash_shell", &shell);
       shell->LockScreen();
     }
     else if (sender == widgets_button_) {
@@ -331,7 +331,7 @@ class WindowTypeLauncherView : public views::WidgetDelegateView,
     }
   }
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   views::LabelButton* create_button_;
   views::LabelButton* panel_button_;
   views::LabelButton* create_nonresizable_button_;
@@ -355,15 +355,16 @@ class WindowTypeLauncherView : public views::WidgetDelegateView,
 WindowTypeLauncher::WindowTypeLauncher() {}
 WindowTypeLauncher::~WindowTypeLauncher() {}
 
-void WindowTypeLauncher::Initialize(mojo::Shell* shell, const std::string& url,
+void WindowTypeLauncher::Initialize(mojo::Connector* connector,
+                                    const std::string& url,
                                     uint32_t id, uint32_t user_id) {
-  aura_init_.reset(new views::AuraInit(shell, "views_mus_resources.pak"));
+  aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
 
-  views::WindowManagerConnection::Create(shell);
+  views::WindowManagerConnection::Create(connector);
 
   views::Widget* widget = new views::Widget;
   views::Widget::InitParams params(views::Widget::InitParams::TYPE_WINDOW);
-  params.delegate = new WindowTypeLauncherView(shell);
+  params.delegate = new WindowTypeLauncherView(connector);
   widget->Init(params);
   widget->Show();
 }
diff --git a/mash/example/window_type_launcher/window_type_launcher.h b/mash/example/window_type_launcher/window_type_launcher.h
index 610c528..b162db7 100644
--- a/mash/example/window_type_launcher/window_type_launcher.h
+++ b/mash/example/window_type_launcher/window_type_launcher.h
@@ -20,7 +20,7 @@ class WindowTypeLauncher : public mojo::ShellClient {
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
 
   scoped_ptr<views::AuraInit> aura_init_;
diff --git a/mash/quick_launch/quick_launch_application.cc b/mash/quick_launch/quick_launch_application.cc
index 8753f50..d378d9e 100644
--- a/mash/quick_launch/quick_launch_application.cc
+++ b/mash/quick_launch/quick_launch_application.cc
@@ -10,7 +10,7 @@
 #include "mojo/public/c/system/main.h"
 #include "mojo/services/tracing/public/cpp/tracing_impl.h"
 #include "mojo/shell/public/cpp/application_runner.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "ui/views/background.h"
 #include "ui/views/controls/textfield/textfield.h"
@@ -30,8 +30,8 @@ namespace quick_launch {
 class QuickLaunchUI : public views::WidgetDelegateView,
                       public views::TextfieldController {
  public:
-  QuickLaunchUI(mojo::Shell* shell)
-      : shell_(shell), prompt_(new views::Textfield) {
+  QuickLaunchUI(mojo::Connector* connector)
+      : connector_(connector), prompt_(new views::Textfield) {
     set_background(views::Background::CreateStandardPanelBackground());
     prompt_->set_controller(this);
     AddChildView(prompt_);
@@ -63,7 +63,7 @@ class QuickLaunchUI : public views::WidgetDelegateView,
                       const ui::KeyEvent& key_event) override {
     if (key_event.key_code() == ui::VKEY_RETURN) {
       std::string url = Canonicalize(prompt_->text());
-      connections_.push_back(shell_->Connect(url));
+      connections_.push_back(connector_->Connect(url));
       prompt_->SetText(base::string16());
     }
     return false;
@@ -78,7 +78,7 @@ class QuickLaunchUI : public views::WidgetDelegateView,
     return base::UTF16ToUTF8(working);
   }
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   views::Textfield* prompt_;
   std::vector<scoped_ptr<mojo::Connection>> connections_;
 
@@ -88,17 +88,17 @@ class QuickLaunchUI : public views::WidgetDelegateView,
 QuickLaunchApplication::QuickLaunchApplication() {}
 QuickLaunchApplication::~QuickLaunchApplication() {}
 
-void QuickLaunchApplication::Initialize(mojo::Shell* shell,
+void QuickLaunchApplication::Initialize(mojo::Connector* connector,
                                         const std::string& url,
                                         uint32_t id,
                                         uint32_t user_id) {
-  tracing_.Initialize(shell, url);
+  tracing_.Initialize(connector, url);
 
-  aura_init_.reset(new views::AuraInit(shell, "views_mus_resources.pak"));
-  views::WindowManagerConnection::Create(shell);
+  aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
+  views::WindowManagerConnection::Create(connector);
 
   views::Widget* window = views::Widget::CreateWindowWithBounds(
-      new QuickLaunchUI(shell), gfx::Rect(10, 640, 0, 0));
+      new QuickLaunchUI(connector), gfx::Rect(10, 640, 0, 0));
   window->Show();
 }
 
diff --git a/mash/quick_launch/quick_launch_application.h b/mash/quick_launch/quick_launch_application.h
index 07a6eba..c95f2a2 100644
--- a/mash/quick_launch/quick_launch_application.h
+++ b/mash/quick_launch/quick_launch_application.h
@@ -24,7 +24,7 @@ class QuickLaunchApplication : public mojo::ShellClient {
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell,
+  void Initialize(mojo::Connector* connector,
                   const std::string& url,
                   uint32_t id,
                   uint32_t user_id) override;
diff --git a/mash/screenlock/screenlock.cc b/mash/screenlock/screenlock.cc
index e525664..e3bd229 100644
--- a/mash/screenlock/screenlock.cc
+++ b/mash/screenlock/screenlock.cc
@@ -10,7 +10,7 @@
 #include "mash/shell/public/interfaces/shell.mojom.h"
 #include "mash/wm/public/interfaces/container.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/views/background.h"
 #include "ui/views/controls/button/label_button.h"
 #include "ui/views/mus/aura_init.h"
@@ -25,8 +25,8 @@ namespace {
 class ScreenlockView : public views::WidgetDelegateView,
                        public views::ButtonListener {
  public:
-  explicit ScreenlockView(mojo::Shell* shell)
-      : shell_(shell),
+  explicit ScreenlockView(mojo::Connector* connector)
+      : connector_(connector),
         unlock_button_(
             new views::LabelButton(this, base::ASCIIToUTF16("Unlock"))) {
     set_background(views::Background::CreateSolidBackground(SK_ColorYELLOW));
@@ -60,11 +60,11 @@ class ScreenlockView : public views::WidgetDelegateView,
   void ButtonPressed(views::Button* sender, const ui::Event& event) override {
     DCHECK_EQ(sender, unlock_button_);
     mash::shell::mojom::ShellPtr shell;
-    shell_->ConnectToInterface("mojo:mash_shell", &shell);
+    connector_->ConnectToInterface("mojo:mash_shell", &shell);
     shell->UnlockScreen();
   }
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   views::LabelButton* unlock_button_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenlockView);
@@ -72,26 +72,25 @@ class ScreenlockView : public views::WidgetDelegateView,
 
 }  // namespace
 
-Screenlock::Screenlock() : shell_(nullptr) {}
+Screenlock::Screenlock() {}
 Screenlock::~Screenlock() {}
 
-void Screenlock::Initialize(mojo::Shell* shell, const std::string& url,
+void Screenlock::Initialize(mojo::Connector* connector, const std::string& url,
                             uint32_t id, uint32_t user_id) {
-  shell_ = shell;
-  tracing_.Initialize(shell, url);
+  tracing_.Initialize(connector, url);
 
   mash::shell::mojom::ShellPtr mash_shell;
-  shell_->ConnectToInterface("mojo:mash_shell", &mash_shell);
+  connector->ConnectToInterface("mojo:mash_shell", &mash_shell);
   mash_shell->AddScreenlockStateListener(
       bindings_.CreateInterfacePtrAndBind(this));
 
-  aura_init_.reset(new views::AuraInit(shell, "views_mus_resources.pak"));
-  views::WindowManagerConnection::Create(shell);
+  aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
+  views::WindowManagerConnection::Create(connector);
 
   views::Widget* widget = new views::Widget;
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
-  params.delegate = new ScreenlockView(shell);
+  params.delegate = new ScreenlockView(connector);
 
   std::map<std::string, std::vector<uint8_t>> properties;
   properties[mash::wm::mojom::kWindowContainer_Property] =
@@ -100,14 +99,14 @@ void Screenlock::Initialize(mojo::Shell* shell, const std::string& url,
   mus::Window* window =
       views::WindowManagerConnection::Get()->NewWindow(properties);
   params.native_widget = new views::NativeWidgetMus(
-      widget, shell, window, mus::mojom::SurfaceType::DEFAULT);
+      widget, connector, window, mus::mojom::SurfaceType::DEFAULT);
   widget->Init(params);
   widget->Show();
 }
 
 void Screenlock::ScreenlockStateChanged(bool screen_locked) {
   if (!screen_locked)
-    shell_->Quit();
+    base::MessageLoop::current()->QuitWhenIdle();
 }
 
 }  // namespace screenlock
diff --git a/mash/screenlock/screenlock.h b/mash/screenlock/screenlock.h
index e05a46c..e87995f 100644
--- a/mash/screenlock/screenlock.h
+++ b/mash/screenlock/screenlock.h
@@ -29,13 +29,12 @@ class Screenlock : public mojo::ShellClient,
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
 
   // mash::shell::mojom::ScreenlockStateListener:
   void ScreenlockStateChanged(bool locked) override;
 
-  mojo::Shell* shell_;
   mojo::TracingImpl tracing_;
   scoped_ptr<views::AuraInit> aura_init_;
   mojo::BindingSet<mash::shell::mojom::ScreenlockStateListener> bindings_;
diff --git a/mash/shell/shell_application_delegate.cc b/mash/shell/shell_application_delegate.cc
index 9972514..c37dac9 100644
--- a/mash/shell/shell_application_delegate.cc
+++ b/mash/shell/shell_application_delegate.cc
@@ -7,21 +7,21 @@
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace mash {
 namespace shell {
 
 ShellApplicationDelegate::ShellApplicationDelegate()
-    : shell_(nullptr), screen_locked_(false) {}
+    : connector_(nullptr), screen_locked_(false) {}
 
 ShellApplicationDelegate::~ShellApplicationDelegate() {}
 
-void ShellApplicationDelegate::Initialize(mojo::Shell* shell,
+void ShellApplicationDelegate::Initialize(mojo::Connector* connector,
                                           const std::string& url,
                                           uint32_t id,
                                           uint32_t user_id) {
-  shell_ = shell;
+  connector_ = connector;
   StartBrowserDriver();
   StartWindowManager();
   StartSystemUI();
@@ -111,7 +111,7 @@ void ShellApplicationDelegate::StartRestartableService(
     const base::Closure& restart_callback) {
   // TODO(beng): This would be the place to insert logic that counted restarts
   //             to avoid infinite crash-restart loops.
-  scoped_ptr<mojo::Connection> connection = shell_->Connect(url);
+  scoped_ptr<mojo::Connection> connection = connector_->Connect(url);
   // Note: |connection| may be null if we've lost our connection to the shell.
   if (connection) {
     connection->SetRemoteInterfaceProviderConnectionErrorHandler(
diff --git a/mash/shell/shell_application_delegate.h b/mash/shell/shell_application_delegate.h
index 524a554..a429f34a 100644
--- a/mash/shell/shell_application_delegate.h
+++ b/mash/shell/shell_application_delegate.h
@@ -33,7 +33,7 @@ class ShellApplicationDelegate
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
@@ -60,7 +60,7 @@ class ShellApplicationDelegate
   void StartRestartableService(const std::string& url,
                                const base::Closure& restart_callback);
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   std::map<std::string, scoped_ptr<mojo::Connection>> connections_;
   bool screen_locked_;
   mojo::BindingSet<mash::shell::mojom::Shell> bindings_;
diff --git a/mash/task_viewer/task_viewer.cc b/mash/task_viewer/task_viewer.cc
index 552104f..1c2340e 100644
--- a/mash/task_viewer/task_viewer.cc
+++ b/mash/task_viewer/task_viewer.cc
@@ -16,7 +16,7 @@
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/services/package_manager/public/interfaces/catalog.mojom.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/interfaces/application_manager.mojom.h"
 #include "ui/base/models/table_model.h"
 #include "ui/views/background.h"
@@ -42,11 +42,9 @@ class TaskViewerContents
       public mojo::shell::mojom::ApplicationManagerListener {
  public:
   TaskViewerContents(ListenerRequest request,
-                     package_manager::mojom::CatalogPtr catalog,
-                     scoped_ptr<mojo::AppRefCount> app)
+                     package_manager::mojom::CatalogPtr catalog)
       : binding_(this, std::move(request)),
         catalog_(std::move(catalog)),
-        app_(std::move(app)),
         table_view_(nullptr),
         table_view_parent_(nullptr),
         kill_button_(
@@ -69,6 +67,7 @@ class TaskViewerContents
   }
   ~TaskViewerContents() override {
     table_view_->SetModel(nullptr);
+    base::MessageLoop::current()->QuitWhenIdle();
   }
 
  private:
@@ -246,7 +245,6 @@ class TaskViewerContents
 
   mojo::Binding<mojo::shell::mojom::ApplicationManagerListener> binding_;
   package_manager::mojom::CatalogPtr catalog_;
-  scoped_ptr<mojo::AppRefCount> app_;
 
   views::TableView* table_view_;
   views::View* table_view_parent_;
@@ -265,25 +263,26 @@ class TaskViewerContents
 TaskViewer::TaskViewer() {}
 TaskViewer::~TaskViewer() {}
 
-void TaskViewer::Initialize(mojo::Shell* shell, const std::string& url,
+void TaskViewer::Initialize(mojo::Connector* connector,
+                            const std::string& url,
                             uint32_t id, uint32_t user_id) {
-  tracing_.Initialize(shell, url);
+  tracing_.Initialize(connector, url);
 
-  aura_init_.reset(new views::AuraInit(shell, "views_mus_resources.pak"));
-  views::WindowManagerConnection::Create(shell);
+  aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
+  views::WindowManagerConnection::Create(connector);
 
   mojo::shell::mojom::ApplicationManagerPtr application_manager;
-  shell->ConnectToInterface("mojo:shell", &application_manager);
+  connector->ConnectToInterface("mojo:shell", &application_manager);
 
   mojo::shell::mojom::ApplicationManagerListenerPtr listener;
   ListenerRequest request = GetProxy(&listener);
   application_manager->AddListener(std::move(listener));
 
   package_manager::mojom::CatalogPtr catalog;
-  shell->ConnectToInterface("mojo:package_manager", &catalog);
+  connector->ConnectToInterface("mojo:package_manager", &catalog);
 
   TaskViewerContents* task_viewer = new TaskViewerContents(
-      std::move(request), std::move(catalog), shell->CreateAppRefCount());
+      std::move(request), std::move(catalog));
   views::Widget* window = views::Widget::CreateWindowWithBounds(
       task_viewer, gfx::Rect(10, 10, 500, 500));
   window->Show();
diff --git a/mash/task_viewer/task_viewer.h b/mash/task_viewer/task_viewer.h
index 0af60ef..5de6028 100644
--- a/mash/task_viewer/task_viewer.h
+++ b/mash/task_viewer/task_viewer.h
@@ -27,7 +27,7 @@ class TaskViewer : public mojo::ShellClient {
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
 
   mojo::TracingImpl tracing_;
diff --git a/mash/wm/accelerator_registrar_apptest.cc b/mash/wm/accelerator_registrar_apptest.cc
index f7c31ae..a16d210 100644
--- a/mash/wm/accelerator_registrar_apptest.cc
+++ b/mash/wm/accelerator_registrar_apptest.cc
@@ -72,7 +72,7 @@ class AcceleratorRegistrarTest : public mojo::test::ApplicationTestBase {
 
  protected:
   void ConnectToRegistrar(AcceleratorRegistrarPtr* registrar) {
-    shell()->ConnectToInterface("mojo:desktop_wm", registrar);
+    connector()->ConnectToInterface("mojo:desktop_wm", registrar);
   }
 
  private:
diff --git a/mash/wm/non_client_frame_controller.cc b/mash/wm/non_client_frame_controller.cc
index b35741f..ed6ad3a 100644
--- a/mash/wm/non_client_frame_controller.cc
+++ b/mash/wm/non_client_frame_controller.cc
@@ -90,9 +90,9 @@ class ContentWindowLayoutManager : public aura::LayoutManager {
 class WmNativeWidgetMus : public views::NativeWidgetMus {
  public:
   WmNativeWidgetMus(views::internal::NativeWidgetDelegate* delegate,
-                    mojo::Shell* shell,
+                    mojo::Connector* connector,
                     mus::Window* window)
-      : NativeWidgetMus(delegate, shell, window,
+      : NativeWidgetMus(delegate, connector, window,
                         mus::mojom::SurfaceType::UNDERLAY) {}
   ~WmNativeWidgetMus() override {
   }
@@ -166,7 +166,7 @@ class ClientViewMus : public views::ClientView {
 }  // namespace
 
 NonClientFrameController::NonClientFrameController(
-    mojo::Shell* shell,
+    mojo::Connector* connector,
     mus::Window* window,
     mus::WindowManagerClient* window_manager_client)
     : widget_(new views::Widget), window_(window) {
@@ -176,7 +176,7 @@ NonClientFrameController::NonClientFrameController(
   // We initiate focus at the mus level, not at the views level.
   params.activatable = views::Widget::InitParams::ACTIVATABLE_NO;
   params.delegate = this;
-  params.native_widget = new WmNativeWidgetMus(widget_, shell, window);
+  params.native_widget = new WmNativeWidgetMus(widget_, connector, window);
   widget_->Init(params);
   widget_->ShowInactive();
 
diff --git a/mash/wm/non_client_frame_controller.h b/mash/wm/non_client_frame_controller.h
index b5346f2..c43cf73 100644
--- a/mash/wm/non_client_frame_controller.h
+++ b/mash/wm/non_client_frame_controller.h
@@ -17,7 +17,7 @@ class Insets;
 }
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -33,7 +33,7 @@ class NonClientFrameController : public views::WidgetDelegateView,
                                  public mus::WindowObserver {
  public:
   // NonClientFrameController deletes itself when |window| is destroyed.
-  NonClientFrameController(mojo::Shell* shell,
+  NonClientFrameController(mojo::Connector* connector,
                            mus::Window* window,
                            mus::WindowManagerClient* window_manager_client);
 
diff --git a/mash/wm/root_window_controller.cc b/mash/wm/root_window_controller.cc
index d46cd78..03de79e 100644
--- a/mash/wm/root_window_controller.cc
+++ b/mash/wm/root_window_controller.cc
@@ -21,7 +21,7 @@
 #include "mash/wm/window_layout.h"
 #include "mash/wm/window_manager.h"
 #include "mash/wm/window_manager_application.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace mash {
 namespace wm {
@@ -39,7 +39,7 @@ void AssertTrue(bool success) {
 RootWindowController* RootWindowController::CreateUsingWindowTreeHost(
     WindowManagerApplication* app) {
   RootWindowController* controller = new RootWindowController(app);
-  mus::CreateWindowTreeHost(app->shell(), controller,
+  mus::CreateWindowTreeHost(app->connector(), controller,
                             &controller->window_tree_host_,
                             controller->window_manager_.get());
   return controller;
@@ -69,8 +69,8 @@ void RootWindowController::Destroy() {
   }
 }
 
-mojo::Shell* RootWindowController::GetShell() {
-  return app_->shell();
+mojo::Connector* RootWindowController::GetConnector() {
+  return app_->connector();
 }
 
 mus::Window* RootWindowController::GetWindowForContainer(
@@ -145,7 +145,7 @@ void RootWindowController::OnEmbed(mus::Window* root) {
   AddAccelerators();
 
   mash::shell::mojom::ShellPtr shell;
-  app_->shell()->ConnectToInterface("mojo:mash_shell", &shell);
+  app_->connector()->ConnectToInterface("mojo:mash_shell", &shell);
   window_manager_->Initialize(this, std::move(shell));
 
   shadow_controller_.reset(new ShadowController(root->connection()));
diff --git a/mash/wm/root_window_controller.h b/mash/wm/root_window_controller.h
index 623b2e1..d254da5 100644
--- a/mash/wm/root_window_controller.h
+++ b/mash/wm/root_window_controller.h
@@ -13,7 +13,7 @@
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -45,7 +45,7 @@ class RootWindowController : public mus::WindowObserver,
   // Deletes this.
   void Destroy();
 
-  mojo::Shell* GetShell();
+  mojo::Connector* GetConnector();
 
   mus::Window* root() { return root_; }
 
diff --git a/mash/wm/window_manager.cc b/mash/wm/window_manager.cc
index d5b28a8..f57af0a 100644
--- a/mash/wm/window_manager.cc
+++ b/mash/wm/window_manager.cc
@@ -113,7 +113,7 @@ mus::Window* WindowManager::NewTopLevelWindow(
 
   if (provide_non_client_frame) {
     // NonClientFrameController deletes itself when |window| is destroyed.
-    new NonClientFrameController(root_controller_->GetShell(), window,
+    new NonClientFrameController(root_controller_->GetConnector(), window,
                                  root_controller_->window_manager_client());
   }
 
diff --git a/mash/wm/window_manager_application.cc b/mash/wm/window_manager_application.cc
index f02f613..5f5089a 100644
--- a/mash/wm/window_manager_application.cc
+++ b/mash/wm/window_manager_application.cc
@@ -16,7 +16,7 @@
 #include "mash/wm/user_window_controller_impl.h"
 #include "mojo/services/tracing/public/cpp/tracing_impl.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/mojo/init/ui_init.h"
 #include "ui/views/mus/aura_init.h"
 #include "ui/views/mus/display_converter.h"
@@ -25,7 +25,7 @@ namespace mash {
 namespace wm {
 
 WindowManagerApplication::WindowManagerApplication()
-    : shell_(nullptr), window_manager_factory_binding_(this) {}
+    : connector_(nullptr), window_manager_factory_binding_(this) {}
 
 WindowManagerApplication::~WindowManagerApplication() {
   // AcceleratorRegistrarImpl removes an observer in its destructor. Destroy
@@ -56,7 +56,7 @@ void WindowManagerApplication::OnRootWindowControllerGotRoot(
 
   ui_init_.reset(new ui::mojo::UIInit(
       views::GetDisplaysFromWindow(root_controller->root())));
-  aura_init_.reset(new views::AuraInit(shell_, "mash_wm_resources.pak"));
+  aura_init_.reset(new views::AuraInit(connector_, "mash_wm_resources.pak"));
 }
 
 void WindowManagerApplication::OnRootWindowControllerDoneInit(
@@ -103,15 +103,15 @@ void WindowManagerApplication::OnAcceleratorRegistrarDestroyed(
   accelerator_registrars_.erase(registrar);
 }
 
-void WindowManagerApplication::Initialize(mojo::Shell* shell,
+void WindowManagerApplication::Initialize(mojo::Connector* connector,
                                           const std::string& url,
                                           uint32_t id,
                                           uint32_t user_id) {
-  shell_ = shell;
-  tracing_.Initialize(shell, url);
+  connector_ = connector;
+  tracing_.Initialize(connector, url);
 
   mus::mojom::WindowManagerFactoryServicePtr wm_factory_service;
-  shell_->ConnectToInterface("mojo:mus", &wm_factory_service);
+  connector_->ConnectToInterface("mojo:mus", &wm_factory_service);
   wm_factory_service->SetWindowManagerFactory(
       window_manager_factory_binding_.CreateInterfacePtrAndBind());
 
diff --git a/mash/wm/window_manager_application.h b/mash/wm/window_manager_application.h
index 7f2806f..a716990 100644
--- a/mash/wm/window_manager_application.h
+++ b/mash/wm/window_manager_application.h
@@ -50,7 +50,7 @@ class WindowManagerApplication
   WindowManagerApplication();
   ~WindowManagerApplication() override;
 
-  mojo::Shell* shell() { return shell_; }
+  mojo::Connector* connector() { return connector_; }
 
   // Returns the RootWindowControllers that have valid roots.
   //
@@ -78,7 +78,7 @@ class WindowManagerApplication
   void OnAcceleratorRegistrarDestroyed(AcceleratorRegistrarImpl* registrar);
 
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
@@ -97,7 +97,7 @@ class WindowManagerApplication
                            mojo::InterfaceRequest<mus::mojom::WindowTreeClient>
                                client_request) override;
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
 
   mojo::TracingImpl tracing_;
 
diff --git a/mash/wm/window_manager_apptest.cc b/mash/wm/window_manager_apptest.cc
index 6e6e9fb..7ea0a25 100644
--- a/mash/wm/window_manager_apptest.cc
+++ b/mash/wm/window_manager_apptest.cc
@@ -39,12 +39,12 @@ TEST_F(WindowManagerAppTest, OpenWindow) {
   WindowTreeDelegateImpl window_tree_delegate;
 
   // Bring up the the desktop_wm.
-  shell()->Connect("mojo:desktop_wm");
+  connector()->Connect("mojo:desktop_wm");
 
   // Connect to mus and create a new top level window. The request goes to
   // the |desktop_wm|, but is async.
   scoped_ptr<mus::WindowTreeConnection> connection(
-      mus::WindowTreeConnection::Create(&window_tree_delegate, shell()));
+      mus::WindowTreeConnection::Create(&window_tree_delegate, connector()));
   mus::Window* top_level_window = connection->NewTopLevelWindow(nullptr);
   ASSERT_TRUE(top_level_window);
   mus::Window* child_window = connection->NewWindow();
diff --git a/media/mojo/services/media_apptest.cc b/media/mojo/services/media_apptest.cc
index 9776508..5c496adb 100644
--- a/media/mojo/services/media_apptest.cc
+++ b/media/mojo/services/media_apptest.cc
@@ -59,7 +59,7 @@ class MediaAppTest : public mojo::test::ApplicationTestBase {
   void SetUp() override {
     ApplicationTestBase::SetUp();
 
-    connection_ = shell()->Connect("mojo:media");
+    connection_ = connector()->Connect("mojo:media");
     connection_->SetRemoteInterfaceProviderConnectionErrorHandler(
         base::Bind(&MediaAppTest::ConnectionClosed, base::Unretained(this)));
 
diff --git a/media/mojo/services/mojo_media_application.cc b/media/mojo/services/mojo_media_application.cc
index d954bdd..0def56a 100644
--- a/media/mojo/services/mojo_media_application.cc
+++ b/media/mojo/services/mojo_media_application.cc
@@ -10,7 +10,7 @@
 #include "media/mojo/services/mojo_media_client.h"
 #include "media/mojo/services/service_factory_impl.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace media {
 
@@ -18,18 +18,18 @@ namespace media {
 MojoMediaApplication::MojoMediaApplication(
     scoped_ptr<MojoMediaClient> mojo_media_client)
     : mojo_media_client_(std::move(mojo_media_client)),
-      shell_(nullptr),
+      connector_(nullptr),
       media_log_(new MediaLog()) {
   DCHECK(mojo_media_client_);
 }
 
 MojoMediaApplication::~MojoMediaApplication() {}
 
-void MojoMediaApplication::Initialize(mojo::Shell* shell,
+void MojoMediaApplication::Initialize(mojo::Connector* connector,
                                       const std::string& /* url */,
                                       uint32_t /* id */,
                                       uint32_t user_id) {
-  shell_ = shell;
+  connector_ = connector;
   mojo_media_client_->Initialize();
 }
 
@@ -43,7 +43,7 @@ void MojoMediaApplication::Create(
     mojo::InterfaceRequest<interfaces::ServiceFactory> request) {
   // The created object is owned by the pipe.
   new ServiceFactoryImpl(std::move(request), connection->GetRemoteInterfaces(),
-                         media_log_, shell_->CreateAppRefCount(),
+                         media_log_, ref_factory_.CreateRef(),
                          mojo_media_client_.get());
 }
 
diff --git a/media/mojo/services/mojo_media_application.h b/media/mojo/services/mojo_media_application.h
index ece3264..cd5f803 100644
--- a/media/mojo/services/mojo_media_application.h
+++ b/media/mojo/services/mojo_media_application.h
@@ -8,7 +8,8 @@
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "media/mojo/interfaces/service_factory.mojom.h"
-#include "mojo/shell/public/cpp/interface_factory_impl.h"
+#include "mojo/shell/public/cpp/interface_factory.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "url/gurl.h"
 
@@ -26,7 +27,7 @@ class MojoMediaApplication
 
  private:
   // mojo::ShellClient implementation.
-  void Initialize(mojo::Shell* shell,
+  void Initialize(mojo::Connector* connector,
                   const std::string& url,
                   uint32_t id,
                   uint32_t user_id) final;
@@ -41,8 +42,9 @@ class MojoMediaApplication
   // a scoped_ptr here.
   scoped_ptr<MojoMediaClient> mojo_media_client_;
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   scoped_refptr<MediaLog> media_log_;
+  mojo::MessageLoopRefFactory ref_factory_;
 };
 
 }  // namespace media
diff --git a/media/mojo/services/service_factory_impl.cc b/media/mojo/services/service_factory_impl.cc
index 5782241..28832be 100644
--- a/media/mojo/services/service_factory_impl.cc
+++ b/media/mojo/services/service_factory_impl.cc
@@ -19,7 +19,7 @@ ServiceFactoryImpl::ServiceFactoryImpl(
     mojo::InterfaceRequest<interfaces::ServiceFactory> request,
     mojo::shell::mojom::InterfaceProvider* interfaces,
     scoped_refptr<MediaLog> media_log,
-    scoped_ptr<mojo::AppRefCount> parent_app_refcount,
+    scoped_ptr<mojo::MessageLoopRef> parent_app_refcount,
     MojoMediaClient* mojo_media_client)
     : binding_(this, std::move(request)),
       interfaces_(interfaces),
diff --git a/media/mojo/services/service_factory_impl.h b/media/mojo/services/service_factory_impl.h
index 5120586..37a50ff 100644
--- a/media/mojo/services/service_factory_impl.h
+++ b/media/mojo/services/service_factory_impl.h
@@ -10,10 +10,11 @@
 #include "media/mojo/interfaces/service_factory.mojom.h"
 #include "media/mojo/services/mojo_cdm_service_context.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 
 namespace mojo {
-class AppRefCount;
+class MessageLoopRef;
 namespace shell {
 namespace mojom {
 class InterfaceProvider;
@@ -33,7 +34,7 @@ class ServiceFactoryImpl : public interfaces::ServiceFactory {
   ServiceFactoryImpl(mojo::InterfaceRequest<interfaces::ServiceFactory> request,
                      mojo::shell::mojom::InterfaceProvider* interfaces,
                      scoped_refptr<MediaLog> media_log,
-                     scoped_ptr<mojo::AppRefCount> parent_app_refcount,
+                     scoped_ptr<mojo::MessageLoopRef> parent_app_refcount,
                      MojoMediaClient* mojo_media_client);
   ~ServiceFactoryImpl() final;
 
@@ -52,7 +53,7 @@ class ServiceFactoryImpl : public interfaces::ServiceFactory {
   mojo::StrongBinding<interfaces::ServiceFactory> binding_;
   mojo::shell::mojom::InterfaceProvider* interfaces_;
   scoped_refptr<MediaLog> media_log_;
-  scoped_ptr<mojo::AppRefCount> parent_app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> parent_app_refcount_;
   MojoMediaClient* mojo_media_client_;
 
   scoped_ptr<RendererFactory> renderer_factory_;
diff --git a/media/test/pipeline_integration_test.cc b/media/test/pipeline_integration_test.cc
index 87ee95b..80871f9 100644
--- a/media/test/pipeline_integration_test.cc
+++ b/media/test/pipeline_integration_test.cc
@@ -662,7 +662,7 @@ class PipelineIntegrationTestHost : public mojo::test::ApplicationTestBase,
 
  protected:
   scoped_ptr<Renderer> CreateRenderer() override {
-    shell()->ConnectToInterface("mojo:media", &media_service_factory_);
+    connector()->ConnectToInterface("mojo:media", &media_service_factory_);
 
     interfaces::RendererPtr mojo_renderer;
     media_service_factory_->CreateRenderer(mojo::GetProxy(&mojo_renderer));
diff --git a/mojo/public/cpp/bindings/tests/versioning_apptest.cc b/mojo/public/cpp/bindings/tests/versioning_apptest.cc
index 7c74c45..6b6a3f3 100644
--- a/mojo/public/cpp/bindings/tests/versioning_apptest.cc
+++ b/mojo/public/cpp/bindings/tests/versioning_apptest.cc
@@ -8,7 +8,7 @@
 #include "mojo/public/cpp/system/macros.h"
 #include "mojo/public/interfaces/bindings/tests/versioning_test_client.mojom.h"
 #include "mojo/shell/public/cpp/application_test_base.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace mojo {
 namespace test {
@@ -24,7 +24,7 @@ class VersioningApplicationTest : public ApplicationTestBase {
   void SetUp() override {
     ApplicationTestBase::SetUp();
 
-    shell()->ConnectToInterface("mojo:versioning_test_service", &database_);
+    connector()->ConnectToInterface("mojo:versioning_test_service", &database_);
   }
 
   HumanResourceDatabasePtr database_;
diff --git a/mojo/services/network/cookie_store_impl.cc b/mojo/services/network/cookie_store_impl.cc
index acee535..ebd0c92 100644
--- a/mojo/services/network/cookie_store_impl.cc
+++ b/mojo/services/network/cookie_store_impl.cc
@@ -28,7 +28,7 @@ void AdaptSetCookieCallback(const Callback<void(bool)>& callback,
 
 CookieStoreImpl::CookieStoreImpl(NetworkContext* context,
                                  const GURL& origin,
-                                 scoped_ptr<mojo::AppRefCount> app_refcount,
+                                 scoped_ptr<mojo::MessageLoopRef> app_refcount,
                                  InterfaceRequest<CookieStore> request)
     : context_(context),
       origin_(origin),
diff --git a/mojo/services/network/cookie_store_impl.h b/mojo/services/network/cookie_store_impl.h
index a4dfb09..224490c 100644
--- a/mojo/services/network/cookie_store_impl.h
+++ b/mojo/services/network/cookie_store_impl.h
@@ -8,7 +8,7 @@
 #include "base/macros.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/network/public/interfaces/cookie_store.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "url/gurl.h"
 
 namespace mojo {
@@ -18,7 +18,7 @@ class CookieStoreImpl : public CookieStore {
  public:
   CookieStoreImpl(NetworkContext* context,
                   const GURL& origin,
-                  scoped_ptr<mojo::AppRefCount> app_refcount,
+                  scoped_ptr<mojo::MessageLoopRef> app_refcount,
                   InterfaceRequest<CookieStore> request);
   ~CookieStoreImpl() override;
 
@@ -31,7 +31,7 @@ class CookieStoreImpl : public CookieStore {
 
   NetworkContext* context_;
   GURL origin_;
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
   StrongBinding<CookieStore> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(CookieStoreImpl);
diff --git a/mojo/services/network/http_server_apptest.cc b/mojo/services/network/http_server_apptest.cc
index b7e47dd..24b070a 100644
--- a/mojo/services/network/http_server_apptest.cc
+++ b/mojo/services/network/http_server_apptest.cc
@@ -557,7 +557,7 @@ class HttpServerAppTest : public test::ApplicationTestBase {
     ApplicationTestBase::SetUp();
 
     scoped_ptr<Connection> connection =
-        shell()->Connect("mojo:network_service");
+        connector()->Connect("mojo:network_service");
     connection->GetInterface(&network_service_);
     connection->GetInterface(&web_socket_factory_);
   }
diff --git a/mojo/services/network/http_server_impl.cc b/mojo/services/network/http_server_impl.cc
index cc14221..b7e080a 100644
--- a/mojo/services/network/http_server_impl.cc
+++ b/mojo/services/network/http_server_impl.cc
@@ -27,7 +27,7 @@ const int kBackLog = 10;
 void HttpServerImpl::Create(
     NetAddressPtr local_address,
     HttpServerDelegatePtr delegate,
-    scoped_ptr<mojo::AppRefCount> app_refcount,
+    scoped_ptr<mojo::MessageLoopRef> app_refcount,
     const Callback<void(NetworkErrorPtr, NetAddressPtr)>& callback) {
   HttpServerImpl* http_server =
       new HttpServerImpl(std::move(delegate), std::move(app_refcount));
@@ -42,7 +42,7 @@ void HttpServerImpl::Create(
 }
 
 HttpServerImpl::HttpServerImpl(HttpServerDelegatePtr delegate,
-                               scoped_ptr<mojo::AppRefCount> app_refcount)
+                               scoped_ptr<mojo::MessageLoopRef> app_refcount)
     : delegate_(std::move(delegate)), app_refcount_(std::move(app_refcount)) {
   DCHECK(delegate_);
   delegate_.set_connection_error_handler([this]() { delete this; });
diff --git a/mojo/services/network/http_server_impl.h b/mojo/services/network/http_server_impl.h
index a631146..f79b7a8 100644
--- a/mojo/services/network/http_server_impl.h
+++ b/mojo/services/network/http_server_impl.h
@@ -12,7 +12,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "mojo/services/network/public/interfaces/http_server.mojom.h"
 #include "mojo/services/network/public/interfaces/net_address.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "net/server/http_server.h"
 
 namespace net {
@@ -28,7 +28,7 @@ class HttpServerImpl : public net::HttpServer::Delegate {
   static void Create(
       NetAddressPtr local_address,
       HttpServerDelegatePtr delegate,
-      scoped_ptr<mojo::AppRefCount> app_refcount,
+      scoped_ptr<mojo::MessageLoopRef> app_refcount,
       const Callback<void(NetworkErrorPtr, NetAddressPtr)>& callback);
 
   net::HttpServer* server() { return server_.get(); }
@@ -39,7 +39,7 @@ class HttpServerImpl : public net::HttpServer::Delegate {
   // notified that |delegate|'s pipe is closed. Deleting the object directly
   // before that is okay, too.
   HttpServerImpl(HttpServerDelegatePtr delegate,
-                 scoped_ptr<mojo::AppRefCount> app_refcount);
+                 scoped_ptr<mojo::MessageLoopRef> app_refcount);
   ~HttpServerImpl() override;
 
   int Start(NetAddressPtr local_address);
@@ -55,7 +55,7 @@ class HttpServerImpl : public net::HttpServer::Delegate {
   void OnClose(int connection_id) override;
 
   HttpServerDelegatePtr delegate_;
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
   scoped_ptr<net::HttpServer> server_;
 
   std::map<int, linked_ptr<HttpConnectionImpl>> connections_;
diff --git a/mojo/services/network/network_service_delegate.cc b/mojo/services/network/network_service_delegate.cc
index a3a0ea3..9f54082 100644
--- a/mojo/services/network/network_service_delegate.cc
+++ b/mojo/services/network/network_service_delegate.cc
@@ -31,12 +31,11 @@ const char kUserDataDir[] = "user-data-dir";
 
 namespace mojo {
 
-NetworkServiceDelegate::NetworkServiceDelegate()
-    : shell_(nullptr) {
-}
-
-NetworkServiceDelegate::~NetworkServiceDelegate() {
+NetworkServiceDelegate::NetworkServiceDelegate() {
+  ref_factory_.set_quit_closure(
+      base::Bind(&NetworkServiceDelegate::Quit, base::Unretained(this)));
 }
+NetworkServiceDelegate::~NetworkServiceDelegate() {}
 
 void NetworkServiceDelegate::AddObserver(
     NetworkServiceDelegateObserver* observer) {
@@ -48,10 +47,9 @@ void NetworkServiceDelegate::RemoveObserver(
   observers_.RemoveObserver(observer);
 }
 
-void NetworkServiceDelegate::Initialize(Shell* shell, const std::string& url,
+void NetworkServiceDelegate::Initialize(Connector* connector,
+                                        const std::string& url,
                                         uint32_t id, uint32_t user_id) {
-  shell_ = shell;
-
   // TODO(erg): Find everything else that writes to the filesystem and
   // transition it to proxying mojo:filesystem. We shouldn't have any path
   // calculation code here, but sadly need it until the transition is done. In
@@ -68,7 +66,7 @@ void NetworkServiceDelegate::Initialize(Shell* shell, const std::string& url,
   }
 
   context_.reset(new NetworkContext(base_path, this));
-  tracing_.Initialize(shell_, url);
+  tracing_.Initialize(connector, url);
 }
 
 bool NetworkServiceDelegate::AcceptConnection(Connection* connection) {
@@ -84,37 +82,37 @@ bool NetworkServiceDelegate::ShellConnectionLost() {
   return true;
 }
 
-void NetworkServiceDelegate::Quit() {
-  // Destroy the NetworkContext now as it requires MessageLoop::current() upon
-  // destruction and it is the last moment we know for sure that it is
-  // running.
-  context_.reset();
-}
-
 void NetworkServiceDelegate::Create(Connection* connection,
                                     InterfaceRequest<NetworkService> request) {
-  new NetworkServiceImpl(shell_->CreateAppRefCount(), std::move(request));
+  new NetworkServiceImpl(ref_factory_.CreateRef(), std::move(request));
 }
 
 void NetworkServiceDelegate::Create(Connection* connection,
                                     InterfaceRequest<CookieStore> request) {
   new CookieStoreImpl(
       context_.get(), GURL(connection->GetRemoteApplicationURL()).GetOrigin(),
-      shell_->CreateAppRefCount(), std::move(request));
+      ref_factory_.CreateRef(), std::move(request));
 }
 
 void NetworkServiceDelegate::Create(
     Connection* connection,
     InterfaceRequest<WebSocketFactory> request) {
-  new WebSocketFactoryImpl(context_.get(), shell_->CreateAppRefCount(),
+  new WebSocketFactoryImpl(context_.get(), ref_factory_.CreateRef(),
                            std::move(request));
 }
 
 void NetworkServiceDelegate::Create(
     Connection* connection,
     InterfaceRequest<URLLoaderFactory> request) {
-  new URLLoaderFactoryImpl(context_.get(), shell_->CreateAppRefCount(),
+  new URLLoaderFactoryImpl(context_.get(), ref_factory_.CreateRef(),
                            std::move(request));
 }
 
+void NetworkServiceDelegate::Quit() {
+  // Destroy the NetworkContext now as it requires MessageLoop::current() upon
+  // destruction and it is the last moment we know for sure that it is
+  // running.
+  context_.reset();
+}
+
 }  // namespace mojo
diff --git a/mojo/services/network/network_service_delegate.h b/mojo/services/network/network_service_delegate.h
index 678db5a..4159f2a 100644
--- a/mojo/services/network/network_service_delegate.h
+++ b/mojo/services/network/network_service_delegate.h
@@ -5,6 +5,7 @@
 #ifndef MOJO_SERVICES_NETWORK_NETWORK_SERVICE_DELEGATE_H_
 #define MOJO_SERVICES_NETWORK_NETWORK_SERVICE_DELEGATE_H_
 
+#include "base/macros.h"
 #include "base/observer_list.h"
 #include "base/threading/thread.h"
 #include "mojo/services/network/network_context.h"
@@ -14,7 +15,7 @@
 #include "mojo/services/network/public/interfaces/web_socket_factory.mojom.h"
 #include "mojo/services/tracing/public/cpp/tracing_impl.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 
 namespace mojo {
@@ -34,11 +35,10 @@ class NetworkServiceDelegate : public ShellClient,
 
  private:
   // mojo::ShellClient implementation.
-  void Initialize(Shell* shell, const std::string& url,
+  void Initialize(Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(Connection* connection) override;
   bool ShellConnectionLost() override;
-  void Quit() override;
 
   // InterfaceFactory<NetworkService> implementation.
   void Create(Connection* connection,
@@ -57,13 +57,18 @@ class NetworkServiceDelegate : public ShellClient,
               InterfaceRequest<URLLoaderFactory> request) override;
 
  private:
-  Shell* shell_;
+  void Quit();
+
   mojo::TracingImpl tracing_;
 
   // Observers that want notifications that our worker thread is going away.
   base::ObserverList<NetworkServiceDelegateObserver> observers_;
 
   scoped_ptr<NetworkContext> context_;
+
+  mojo::MessageLoopRefFactory ref_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(NetworkServiceDelegate);
 };
 
 }  // namespace mojo
diff --git a/mojo/services/network/network_service_impl.cc b/mojo/services/network/network_service_impl.cc
index cacaf83..1557da8 100644
--- a/mojo/services/network/network_service_impl.cc
+++ b/mojo/services/network/network_service_impl.cc
@@ -16,7 +16,7 @@
 namespace mojo {
 
 NetworkServiceImpl::NetworkServiceImpl(
-    scoped_ptr<mojo::AppRefCount> app_refcount,
+    scoped_ptr<mojo::MessageLoopRef> app_refcount,
     InterfaceRequest<NetworkService> request)
     : app_refcount_(std::move(app_refcount)),
       binding_(this, std::move(request)) {}
diff --git a/mojo/services/network/network_service_impl.h b/mojo/services/network/network_service_impl.h
index fa5ffe02..014ca0f 100644
--- a/mojo/services/network/network_service_impl.h
+++ b/mojo/services/network/network_service_impl.h
@@ -8,14 +8,14 @@
 #include "base/compiler_specific.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/network/public/interfaces/network_service.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "url/gurl.h"
 
 namespace mojo {
 
 class NetworkServiceImpl : public NetworkService {
  public:
-  NetworkServiceImpl(scoped_ptr<mojo::AppRefCount> app_refcount,
+  NetworkServiceImpl(scoped_ptr<mojo::MessageLoopRef> app_refcount,
                      InterfaceRequest<NetworkService> request);
   ~NetworkServiceImpl() override;
 
@@ -39,7 +39,7 @@ class NetworkServiceImpl : public NetworkService {
       const GetMimeTypeFromFileCallback& callback) override;
 
  private:
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
   StrongBinding<NetworkService> binding_;
 };
 
diff --git a/mojo/services/network/tcp_bound_socket_impl.cc b/mojo/services/network/tcp_bound_socket_impl.cc
index d8a60b7..1d8669f 100644
--- a/mojo/services/network/tcp_bound_socket_impl.cc
+++ b/mojo/services/network/tcp_bound_socket_impl.cc
@@ -15,7 +15,7 @@
 namespace mojo {
 
 TCPBoundSocketImpl::TCPBoundSocketImpl(
-    scoped_ptr<mojo::AppRefCount> app_refcount,
+    scoped_ptr<mojo::MessageLoopRef> app_refcount,
     InterfaceRequest<TCPBoundSocket> request)
     : app_refcount_(std::move(app_refcount)),
       binding_(this, std::move(request)) {}
diff --git a/mojo/services/network/tcp_bound_socket_impl.h b/mojo/services/network/tcp_bound_socket_impl.h
index 5cb256e..8e4b2e8 100644
--- a/mojo/services/network/tcp_bound_socket_impl.h
+++ b/mojo/services/network/tcp_bound_socket_impl.h
@@ -8,14 +8,14 @@
 #include "base/memory/scoped_ptr.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/network/public/interfaces/tcp_bound_socket.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "net/socket/tcp_socket.h"
 
 namespace mojo {
 
 class TCPBoundSocketImpl : public TCPBoundSocket {
  public:
-  TCPBoundSocketImpl(scoped_ptr<mojo::AppRefCount> app_refcount,
+  TCPBoundSocketImpl(scoped_ptr<mojo::MessageLoopRef> app_refcount,
                      InterfaceRequest<TCPBoundSocket> request);
   ~TCPBoundSocketImpl() override;
 
@@ -47,7 +47,7 @@ class TCPBoundSocketImpl : public TCPBoundSocket {
   ScopedDataPipeProducerHandle pending_connect_receive_stream_;
   InterfaceRequest<TCPConnectedSocket> pending_connect_socket_;
   Callback<void(NetworkErrorPtr)> pending_connect_callback_;
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
   StrongBinding<TCPBoundSocket> binding_;
 };
 
diff --git a/mojo/services/network/tcp_connected_socket_impl.cc b/mojo/services/network/tcp_connected_socket_impl.cc
index 8a6d0a0..8da9484 100644
--- a/mojo/services/network/tcp_connected_socket_impl.cc
+++ b/mojo/services/network/tcp_connected_socket_impl.cc
@@ -19,7 +19,7 @@ TCPConnectedSocketImpl::TCPConnectedSocketImpl(
     ScopedDataPipeConsumerHandle send_stream,
     ScopedDataPipeProducerHandle receive_stream,
     InterfaceRequest<TCPConnectedSocket> request,
-    scoped_ptr<mojo::AppRefCount> app_refcount)
+    scoped_ptr<mojo::MessageLoopRef> app_refcount)
     : socket_(std::move(socket)),
       send_stream_(std::move(send_stream)),
       receive_stream_(std::move(receive_stream)),
diff --git a/mojo/services/network/tcp_connected_socket_impl.h b/mojo/services/network/tcp_connected_socket_impl.h
index 4611189..1131bf6 100644
--- a/mojo/services/network/tcp_connected_socket_impl.h
+++ b/mojo/services/network/tcp_connected_socket_impl.h
@@ -10,7 +10,7 @@
 #include "mojo/message_pump/handle_watcher.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/services/network/public/interfaces/tcp_connected_socket.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "net/socket/tcp_socket.h"
 
 namespace mojo {
@@ -24,7 +24,7 @@ class TCPConnectedSocketImpl : public TCPConnectedSocket {
                          ScopedDataPipeConsumerHandle send_stream,
                          ScopedDataPipeProducerHandle receive_stream,
                          InterfaceRequest<TCPConnectedSocket> request,
-                         scoped_ptr<mojo::AppRefCount> app_refcount);
+                         scoped_ptr<mojo::MessageLoopRef> app_refcount);
   ~TCPConnectedSocketImpl() override;
 
  private:
@@ -69,7 +69,7 @@ class TCPConnectedSocketImpl : public TCPConnectedSocket {
   // To bind to the message pipe.
   Binding<TCPConnectedSocket> binding_;
 
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
 
   base::WeakPtrFactory<TCPConnectedSocketImpl> weak_ptr_factory_;
 };
diff --git a/mojo/services/network/tcp_server_socket_impl.cc b/mojo/services/network/tcp_server_socket_impl.cc
index 2762964..a01feff 100644
--- a/mojo/services/network/tcp_server_socket_impl.cc
+++ b/mojo/services/network/tcp_server_socket_impl.cc
@@ -15,7 +15,7 @@ namespace mojo {
 
 TCPServerSocketImpl::TCPServerSocketImpl(
     scoped_ptr<net::TCPSocket> socket,
-    scoped_ptr<mojo::AppRefCount> app_refcount,
+    scoped_ptr<mojo::MessageLoopRef> app_refcount,
     InterfaceRequest<TCPServerSocket> request)
     : socket_(std::move(socket)),
       app_refcount_(std::move(app_refcount)),
diff --git a/mojo/services/network/tcp_server_socket_impl.h b/mojo/services/network/tcp_server_socket_impl.h
index 5149cb1..2078cec 100644
--- a/mojo/services/network/tcp_server_socket_impl.h
+++ b/mojo/services/network/tcp_server_socket_impl.h
@@ -8,7 +8,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/network/public/interfaces/tcp_server_socket.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "net/base/ip_endpoint.h"
 #include "net/socket/tcp_socket.h"
 
@@ -20,7 +20,7 @@ class TCPServerSocketImpl : public TCPServerSocket {
 
   // Passed ownership of a socket already in listening mode.
   TCPServerSocketImpl(scoped_ptr<net::TCPSocket> socket,
-                      scoped_ptr<mojo::AppRefCount> app_refcount,
+                      scoped_ptr<mojo::MessageLoopRef> app_refcount,
                       InterfaceRequest<TCPServerSocket> request);
   ~TCPServerSocketImpl() override;
 
@@ -47,7 +47,7 @@ class TCPServerSocketImpl : public TCPServerSocket {
   scoped_ptr<net::TCPSocket> accepted_socket_;
   net::IPEndPoint accepted_address_;
 
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
   StrongBinding<TCPServerSocket> binding_;
 };
 
diff --git a/mojo/services/network/udp_socket_apptest.cc b/mojo/services/network/udp_socket_apptest.cc
index ac800e0..075a29c 100644
--- a/mojo/services/network/udp_socket_apptest.cc
+++ b/mojo/services/network/udp_socket_apptest.cc
@@ -324,7 +324,7 @@ class UDPSocketAppTest : public test::ApplicationTestBase {
 
   void SetUp() override {
     ApplicationTestBase::SetUp();
-    shell()->ConnectToInterface("mojo:network_service", &network_service_);
+    connector()->ConnectToInterface("mojo:network_service", &network_service_);
     network_service_->CreateUDPSocket(GetProxy(&socket_));
   }
 
diff --git a/mojo/services/network/udp_socket_impl.cc b/mojo/services/network/udp_socket_impl.cc
index f87dcb0..c99f66f 100644
--- a/mojo/services/network/udp_socket_impl.cc
+++ b/mojo/services/network/udp_socket_impl.cc
@@ -37,7 +37,7 @@ UDPSocketImpl::PendingSendRequest::PendingSendRequest() {}
 UDPSocketImpl::PendingSendRequest::~PendingSendRequest() {}
 
 UDPSocketImpl::UDPSocketImpl(InterfaceRequest<UDPSocket> request,
-                             scoped_ptr<mojo::AppRefCount> app_refcount)
+                             scoped_ptr<mojo::MessageLoopRef> app_refcount)
     : binding_(this, std::move(request)),
       socket_(net::DatagramSocket::DEFAULT_BIND,
               net::RandIntCallback(),
diff --git a/mojo/services/network/udp_socket_impl.h b/mojo/services/network/udp_socket_impl.h
index 459ba9d..6ea5770 100644
--- a/mojo/services/network/udp_socket_impl.h
+++ b/mojo/services/network/udp_socket_impl.h
@@ -14,7 +14,7 @@
 #include "base/memory/ref_counted.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/network/public/interfaces/udp_socket.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "net/base/ip_endpoint.h"
 #include "net/udp/udp_socket.h"
 
@@ -30,7 +30,7 @@ class UDPSocketImpl : public UDPSocket {
   // The lifetime of a new UDPSocketImpl is bound to the connection associated
   // with |request|.
   UDPSocketImpl(InterfaceRequest<UDPSocket> request,
-                scoped_ptr<mojo::AppRefCount> app_refcount);
+                scoped_ptr<mojo::MessageLoopRef> app_refcount);
   ~UDPSocketImpl() override;
 
   // UDPSocket implementation.
@@ -123,7 +123,7 @@ class UDPSocketImpl : public UDPSocket {
   // The maximum size of the |pending_send_requests_| queue.
   size_t max_pending_send_requests_;
 
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
 
   DISALLOW_COPY_AND_ASSIGN(UDPSocketImpl);
 };
diff --git a/mojo/services/network/url_loader_factory_impl.cc b/mojo/services/network/url_loader_factory_impl.cc
index b14183c..2e19d5b 100644
--- a/mojo/services/network/url_loader_factory_impl.cc
+++ b/mojo/services/network/url_loader_factory_impl.cc
@@ -12,7 +12,7 @@ namespace mojo {
 
 URLLoaderFactoryImpl::URLLoaderFactoryImpl(
     NetworkContext* context,
-    scoped_ptr<mojo::AppRefCount> app_refcount,
+    scoped_ptr<mojo::MessageLoopRef> app_refcount,
     InterfaceRequest<URLLoaderFactory> request)
     : context_(context),
       app_refcount_(std::move(app_refcount)),
diff --git a/mojo/services/network/url_loader_factory_impl.h b/mojo/services/network/url_loader_factory_impl.h
index 7b12556..0b59208 100644
--- a/mojo/services/network/url_loader_factory_impl.h
+++ b/mojo/services/network/url_loader_factory_impl.h
@@ -9,7 +9,7 @@
 #include "base/macros.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/network/public/interfaces/url_loader_factory.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 
 namespace mojo {
 class NetworkContext;
@@ -17,7 +17,7 @@ class NetworkContext;
 class URLLoaderFactoryImpl : public URLLoaderFactory {
  public:
   URLLoaderFactoryImpl(NetworkContext* context,
-                       scoped_ptr<mojo::AppRefCount> app_refcount,
+                       scoped_ptr<mojo::MessageLoopRef> app_refcount,
                        InterfaceRequest<URLLoaderFactory> request);
   ~URLLoaderFactoryImpl() override;
 
@@ -26,7 +26,7 @@ class URLLoaderFactoryImpl : public URLLoaderFactory {
 
  private:
   NetworkContext* context_;
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
   StrongBinding<URLLoaderFactory> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(URLLoaderFactoryImpl);
diff --git a/mojo/services/network/url_loader_impl.cc b/mojo/services/network/url_loader_impl.cc
index e8727ca..b6db54e 100644
--- a/mojo/services/network/url_loader_impl.cc
+++ b/mojo/services/network/url_loader_impl.cc
@@ -141,7 +141,7 @@ class UploadDataPipeElementReader : public net::UploadElementReader {
 
 URLLoaderImpl::URLLoaderImpl(NetworkContext* context,
                              InterfaceRequest<URLLoader> request,
-                             scoped_ptr<mojo::AppRefCount> app_refcount)
+                             scoped_ptr<mojo::MessageLoopRef> app_refcount)
     : context_(context),
       response_body_buffer_size_(0),
       response_body_bytes_read_(0),
diff --git a/mojo/services/network/url_loader_impl.h b/mojo/services/network/url_loader_impl.h
index b8e6905..833eb86 100644
--- a/mojo/services/network/url_loader_impl.h
+++ b/mojo/services/network/url_loader_impl.h
@@ -12,7 +12,7 @@
 #include "mojo/message_pump/handle_watcher.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/services/network/public/interfaces/url_loader.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "net/base/net_errors.h"
 #include "net/url_request/url_request.h"
 
@@ -26,7 +26,7 @@ class URLLoaderImpl : public URLLoader,
  public:
   URLLoaderImpl(NetworkContext* context,
                 InterfaceRequest<URLLoader> request,
-                scoped_ptr<mojo::AppRefCount> app_refcount);
+                scoped_ptr<mojo::MessageLoopRef> app_refcount);
   ~URLLoaderImpl() override;
 
   // Called when the associated NetworkContext is going away.
@@ -70,7 +70,7 @@ class URLLoaderImpl : public URLLoader,
   bool auto_follow_redirects_;
   bool connected_;
   Binding<URLLoader> binding_;
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
 
   base::WeakPtrFactory<URLLoaderImpl> weak_ptr_factory_;
 };
diff --git a/mojo/services/network/url_loader_impl_apptest.cc b/mojo/services/network/url_loader_impl_apptest.cc
index 90e7c96..fe7bd06 100644
--- a/mojo/services/network/url_loader_impl_apptest.cc
+++ b/mojo/services/network/url_loader_impl_apptest.cc
@@ -14,6 +14,7 @@
 #include "mojo/services/network/network_context.h"
 #include "mojo/services/network/url_loader_impl.h"
 #include "mojo/shell/public/cpp/application_test_base.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 #include "net/base/net_errors.h"
 #include "net/url_request/url_request_job.h"
 #include "net/url_request/url_request_job_factory_impl.h"
@@ -129,7 +130,7 @@ class UrlLoaderImplTest : public test::ApplicationTestBase {
     MessagePipe pipe;
     new URLLoaderImpl(network_context_.get(),
                       GetProxy(&url_loader_proxy_),
-                      make_scoped_ptr<mojo::AppRefCount>(nullptr));
+                      make_scoped_ptr<mojo::MessageLoopRef>(nullptr));
     EXPECT_TRUE(IsUrlLoaderValid());
   }
 
diff --git a/mojo/services/network/web_socket_factory_impl.cc b/mojo/services/network/web_socket_factory_impl.cc
index ecd7272..6adde55 100644
--- a/mojo/services/network/web_socket_factory_impl.cc
+++ b/mojo/services/network/web_socket_factory_impl.cc
@@ -12,7 +12,7 @@ namespace mojo {
 
 WebSocketFactoryImpl::WebSocketFactoryImpl(
     NetworkContext* context,
-    scoped_ptr<AppRefCount> app_refcount,
+    scoped_ptr<MessageLoopRef> app_refcount,
     InterfaceRequest<WebSocketFactory> request)
     : context_(context),
       app_refcount_(std::move(app_refcount)),
diff --git a/mojo/services/network/web_socket_factory_impl.h b/mojo/services/network/web_socket_factory_impl.h
index 2763e7f4..ca254ca 100644
--- a/mojo/services/network/web_socket_factory_impl.h
+++ b/mojo/services/network/web_socket_factory_impl.h
@@ -9,7 +9,7 @@
 #include "base/macros.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/network/public/interfaces/web_socket_factory.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 
 namespace mojo {
 class NetworkContext;
@@ -17,7 +17,7 @@ class NetworkContext;
 class WebSocketFactoryImpl : public WebSocketFactory {
  public:
   WebSocketFactoryImpl(NetworkContext* context,
-                       scoped_ptr<AppRefCount> app_refcount,
+                       scoped_ptr<MessageLoopRef> app_refcount,
                        InterfaceRequest<WebSocketFactory> request);
   ~WebSocketFactoryImpl() override;
 
@@ -26,7 +26,7 @@ class WebSocketFactoryImpl : public WebSocketFactory {
 
  private:
   NetworkContext* context_;
-  scoped_ptr<AppRefCount> app_refcount_;
+  scoped_ptr<MessageLoopRef> app_refcount_;
   StrongBinding<WebSocketFactory> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(WebSocketFactoryImpl);
diff --git a/mojo/services/network/web_socket_impl.cc b/mojo/services/network/web_socket_impl.cc
index 459b531..2d89149 100644
--- a/mojo/services/network/web_socket_impl.cc
+++ b/mojo/services/network/web_socket_impl.cc
@@ -182,7 +182,7 @@ void WebSocketEventHandler::DidWriteToReceiveStream(
 }  // namespace mojo
 
 WebSocketImpl::WebSocketImpl(NetworkContext* context,
-                             scoped_ptr<mojo::AppRefCount> app_refcount,
+                             scoped_ptr<mojo::MessageLoopRef> app_refcount,
                              InterfaceRequest<WebSocket> request)
     : context_(context),
       app_refcount_(std::move(app_refcount)),
diff --git a/mojo/services/network/web_socket_impl.h b/mojo/services/network/web_socket_impl.h
index 30b7cc2..06fd3ca 100644
--- a/mojo/services/network/web_socket_impl.h
+++ b/mojo/services/network/web_socket_impl.h
@@ -10,7 +10,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/services/network/public/interfaces/web_socket.mojom.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/message_loop_ref.h"
 
 namespace net {
 class WebSocketChannel;
@@ -25,7 +25,7 @@ class WebSocketReadQueue;
 class WebSocketImpl : public WebSocket {
  public:
   WebSocketImpl(NetworkContext* context,
-                scoped_ptr<mojo::AppRefCount> app_refcount,
+                scoped_ptr<mojo::MessageLoopRef> app_refcount,
                 InterfaceRequest<WebSocket> request);
   ~WebSocketImpl() override;
 
@@ -51,7 +51,7 @@ class WebSocketImpl : public WebSocket {
   ScopedDataPipeConsumerHandle send_stream_;
   scoped_ptr<WebSocketReadQueue> read_queue_;
   NetworkContext* context_;
-  scoped_ptr<mojo::AppRefCount> app_refcount_;
+  scoped_ptr<mojo::MessageLoopRef> app_refcount_;
   StrongBinding<WebSocket> binding_;
 };
 
diff --git a/mojo/services/package_manager/package_manager.cc b/mojo/services/package_manager/package_manager.cc
index ce6e1a69..54ec917 100644
--- a/mojo/services/package_manager/package_manager.cc
+++ b/mojo/services/package_manager/package_manager.cc
@@ -107,9 +107,6 @@ PackageManager::PackageManager(base::TaskRunner* blocking_pool,
 }
 PackageManager::~PackageManager() {}
 
-void PackageManager::Initialize(mojo::Shell* shell, const std::string& url,
-                                uint32_t id, uint32_t user_id) {}
-
 bool PackageManager::AcceptConnection(mojo::Connection* connection) {
   connection->AddInterface<mojom::Catalog>(this);
   connection->AddInterface<mojom::Resolver>(this);
diff --git a/mojo/services/package_manager/package_manager.h b/mojo/services/package_manager/package_manager.h
index e587cc6..dc36d8e 100644
--- a/mojo/services/package_manager/package_manager.h
+++ b/mojo/services/package_manager/package_manager.h
@@ -14,7 +14,6 @@
 #include "mojo/services/package_manager/public/interfaces/resolver.mojom.h"
 #include "mojo/services/package_manager/public/interfaces/shell_resolver.mojom.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
-#include "mojo/shell/public/cpp/shell.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "url/gurl.h"
 
@@ -80,8 +79,6 @@ class PackageManager : public mojo::ShellClient,
   using MojoURLAliasMap = std::map<GURL, std::pair<GURL, std::string>>;
 
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
-                  uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
   // mojo::InterfaceFactory<mojom::Resolver>:
diff --git a/mojo/services/test_service/test_request_tracker_application.cc b/mojo/services/test_service/test_request_tracker_application.cc
index 73190b00..0b5d27a 100644
--- a/mojo/services/test_service/test_request_tracker_application.cc
+++ b/mojo/services/test_service/test_request_tracker_application.cc
@@ -15,15 +15,14 @@
 namespace mojo {
 namespace test {
 
-TestRequestTrackerApplication::TestRequestTrackerApplication()
-    : shell_(nullptr) {}
+TestRequestTrackerApplication::TestRequestTrackerApplication() {}
 TestRequestTrackerApplication::~TestRequestTrackerApplication() {}
 
-void TestRequestTrackerApplication::Initialize(Shell* shell,
+void TestRequestTrackerApplication::Initialize(Connector* connector,
                                                const std::string& url,
                                                uint32_t id,
                                                uint32_t user_id) {
-  shell_ = shell;
+  connector_ = connector;
 }
 
 bool TestRequestTrackerApplication::AcceptConnection(Connection* connection) {
@@ -38,7 +37,7 @@ bool TestRequestTrackerApplication::AcceptConnection(Connection* connection) {
 void TestRequestTrackerApplication::Create(
     Connection* connection,
     InterfaceRequest<TestTimeService> request) {
-  new TestTimeServiceImpl(shell_, std::move(request));
+  new TestTimeServiceImpl(connector_, std::move(request));
 }
 
 void TestRequestTrackerApplication::Create(
diff --git a/mojo/services/test_service/test_request_tracker_application.h b/mojo/services/test_service/test_request_tracker_application.h
index 22206f9..a3dde4a 100644
--- a/mojo/services/test_service/test_request_tracker_application.h
+++ b/mojo/services/test_service/test_request_tracker_application.h
@@ -26,7 +26,7 @@ class TestRequestTrackerApplication
   ~TestRequestTrackerApplication() override;
 
   // mojo::ShellClient methods:
-  void Initialize(Shell* shell, const std::string& url,
+  void Initialize(Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(Connection* connection) override;
 
@@ -43,7 +43,7 @@ class TestRequestTrackerApplication
               InterfaceRequest<TestTrackedRequestService> request) override;
 
  private:
-  Shell* shell_;
+  Connector* connector_;
   TrackingContext context_;
   MOJO_DISALLOW_COPY_AND_ASSIGN(TestRequestTrackerApplication);
 };
diff --git a/mojo/services/test_service/test_service_application.cc b/mojo/services/test_service/test_service_application.cc
index a447c24..1274c3e 100644
--- a/mojo/services/test_service/test_service_application.cc
+++ b/mojo/services/test_service/test_service_application.cc
@@ -17,15 +17,16 @@ namespace mojo {
 namespace test {
 
 TestServiceApplication::TestServiceApplication()
-    : ref_count_(0), shell_(nullptr) {
+    : ref_count_(0), connector_(nullptr) {
 }
 
 TestServiceApplication::~TestServiceApplication() {
 }
 
-void TestServiceApplication::Initialize(Shell* shell, const std::string& url,
+void TestServiceApplication::Initialize(Connector* connector,
+                                        const std::string& url,
                                         uint32_t id, uint32_t user_id) {
-  shell_ = shell;
+  connector_ = connector;
 }
 
 bool TestServiceApplication::AcceptConnection(Connection* connection) {
@@ -36,13 +37,13 @@ bool TestServiceApplication::AcceptConnection(Connection* connection) {
 
 void TestServiceApplication::Create(Connection* connection,
                                     InterfaceRequest<TestService> request) {
-  new TestServiceImpl(shell_, this, std::move(request));
+  new TestServiceImpl(connector_, this, std::move(request));
   AddRef();
 }
 
 void TestServiceApplication::Create(Connection* connection,
                                     InterfaceRequest<TestTimeService> request) {
-  new TestTimeServiceImpl(shell_, std::move(request));
+  new TestTimeServiceImpl(connector_, std::move(request));
 }
 
 void TestServiceApplication::AddRef() {
diff --git a/mojo/services/test_service/test_service_application.h b/mojo/services/test_service/test_service_application.h
index 1c024c03..840954f 100644
--- a/mojo/services/test_service/test_service_application.h
+++ b/mojo/services/test_service/test_service_application.h
@@ -23,7 +23,7 @@ class TestServiceApplication : public ShellClient,
   ~TestServiceApplication() override;
 
   // mojo::ShellClient implementation.
-  void Initialize(Shell* shell, const std::string& url,
+  void Initialize(Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override;
   bool AcceptConnection(Connection* connection) override;
 
@@ -40,7 +40,7 @@ class TestServiceApplication : public ShellClient,
 
  private:
   int ref_count_;
-  Shell* shell_;
+  Connector* connector_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(TestServiceApplication);
 };
diff --git a/mojo/services/test_service/test_service_impl.cc b/mojo/services/test_service/test_service_impl.cc
index 5582dec..f7c4bd1 100644
--- a/mojo/services/test_service/test_service_impl.cc
+++ b/mojo/services/test_service/test_service_impl.cc
@@ -14,16 +14,16 @@
 #include "mojo/services/test_service/test_service_application.h"
 #include "mojo/services/test_service/test_time_service_impl.h"
 #include "mojo/services/test_service/tracked_service.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace mojo {
 namespace test {
 
-TestServiceImpl::TestServiceImpl(Shell* shell,
+TestServiceImpl::TestServiceImpl(Connector* connector,
                                  TestServiceApplication* application,
                                  InterfaceRequest<TestService> request)
     : application_(application),
-      shell_(shell),
+      connector_(connector),
       binding_(this, std::move(request)) {
   binding_.set_connection_error_handler(
       [this]() { application_->ReleaseRef(); });
@@ -47,7 +47,7 @@ void SendTimeResponse(
 void TestServiceImpl::ConnectToAppAndGetTime(
     const mojo::String& app_url,
     const mojo::Callback<void(int64_t)>& callback) {
-  shell_->ConnectToInterface(app_url.get(), &time_service_);
+  connector_->ConnectToInterface(app_url.get(), &time_service_);
   if (tracking_) {
     tracking_->RecordNewRequest();
     time_service_->StartTrackingRequests(mojo::Callback<void()>());
@@ -58,7 +58,7 @@ void TestServiceImpl::ConnectToAppAndGetTime(
 void TestServiceImpl::StartTrackingRequests(
     const mojo::Callback<void()>& callback) {
   TestRequestTrackerPtr tracker;
-  shell_->ConnectToInterface("mojo:test_request_tracker_app", &tracker);
+  connector_->ConnectToInterface("mojo:test_request_tracker_app", &tracker);
   tracking_.reset(new TrackedService(std::move(tracker), Name_, callback));
 }
 
diff --git a/mojo/services/test_service/test_service_impl.h b/mojo/services/test_service/test_service_impl.h
index f96da3c..60ba795 100644
--- a/mojo/services/test_service/test_service_impl.h
+++ b/mojo/services/test_service/test_service_impl.h
@@ -13,7 +13,7 @@
 #include "mojo/services/test_service/test_service.mojom.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 namespace test {
 
 class TrackedService;
@@ -21,7 +21,7 @@ class TestServiceApplication;
 
 class TestServiceImpl : public TestService {
  public:
-  TestServiceImpl(Shell* shell,
+  TestServiceImpl(Connector* connector,
                   TestServiceApplication* application,
                   InterfaceRequest<TestService> request);
   ~TestServiceImpl() override;
@@ -35,7 +35,7 @@ class TestServiceImpl : public TestService {
 
  private:
   TestServiceApplication* const application_;
-  Shell* const shell_;
+  Connector* const connector_;
   TestTimeServicePtr time_service_;
   scoped_ptr<TrackedService> tracking_;
   StrongBinding<TestService> binding_;
diff --git a/mojo/services/test_service/test_time_service_impl.cc b/mojo/services/test_service/test_time_service_impl.cc
index ee4028d..3074e59 100644
--- a/mojo/services/test_service/test_time_service_impl.cc
+++ b/mojo/services/test_service/test_time_service_impl.cc
@@ -11,15 +11,15 @@
 #include "base/time/time.h"
 #include "mojo/services/test_service/test_request_tracker.mojom.h"
 #include "mojo/services/test_service/tracked_service.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 namespace mojo {
 namespace test {
 
 TestTimeServiceImpl::TestTimeServiceImpl(
-      Shell* shell,
+      Connector* connector,
       InterfaceRequest<TestTimeService> request)
-    : shell_(shell), binding_(this, std::move(request)) {}
+    : connector_(connector), binding_(this, std::move(request)) {}
 
 TestTimeServiceImpl::~TestTimeServiceImpl() {
 }
@@ -27,7 +27,7 @@ TestTimeServiceImpl::~TestTimeServiceImpl() {
 void TestTimeServiceImpl::StartTrackingRequests(
     const mojo::Callback<void()>& callback) {
   TestRequestTrackerPtr tracker;
-  shell_->ConnectToInterface("mojo:test_request_tracker_app", &tracker);
+  connector_->ConnectToInterface("mojo:test_request_tracker_app", &tracker);
   tracking_.reset(new TrackedService(std::move(tracker), Name_, callback));
 }
 
diff --git a/mojo/services/test_service/test_time_service_impl.h b/mojo/services/test_service/test_time_service_impl.h
index 6b50982..d590a05 100644
--- a/mojo/services/test_service/test_time_service_impl.h
+++ b/mojo/services/test_service/test_time_service_impl.h
@@ -15,7 +15,7 @@
 
 namespace mojo {
 class Connection;
-class Shell;
+class Connector;
 
 namespace test {
 
@@ -23,7 +23,7 @@ class TrackedService;
 
 class TestTimeServiceImpl : public TestTimeService {
  public:
-  TestTimeServiceImpl(Shell* shell, InterfaceRequest<TestTimeService> request);
+  TestTimeServiceImpl(Connector* connector, TestTimeServiceRequest request);
   ~TestTimeServiceImpl() override;
 
   // |TestTimeService| methods:
@@ -32,7 +32,7 @@ class TestTimeServiceImpl : public TestTimeService {
   void StartTrackingRequests(const mojo::Callback<void()>& callback) override;
 
  private:
-  Shell* shell_;
+  Connector* connector_;
   scoped_ptr<TrackedService> tracking_;
   StrongBinding<TestTimeService> binding_;
   MOJO_DISALLOW_COPY_AND_ASSIGN(TestTimeServiceImpl);
diff --git a/mojo/services/tracing/public/cpp/tracing_impl.cc b/mojo/services/tracing/public/cpp/tracing_impl.cc
index 2ac2749..e7a369c 100644
--- a/mojo/services/tracing/public/cpp/tracing_impl.cc
+++ b/mojo/services/tracing/public/cpp/tracing_impl.cc
@@ -10,7 +10,7 @@
 #include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
 #include "base/trace_event/trace_event_impl.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 
 #ifdef NDEBUG
 #include "base/command_line.h"
@@ -41,7 +41,7 @@ TracingImpl::TracingImpl() {
 TracingImpl::~TracingImpl() {
 }
 
-void TracingImpl::Initialize(Shell* shell, const std::string& url) {
+void TracingImpl::Initialize(Connector* connector, const std::string& url) {
   {
     base::AutoLock lock(g_singleton_lock.Get());
     if (g_tracing_singleton_created)
@@ -53,7 +53,7 @@ void TracingImpl::Initialize(Shell* shell, const std::string& url) {
   // up to something like CoreServices to name its own child threads.
   base::PlatformThread::SetName(url);
 
-  connection_ = shell->Connect("mojo:tracing");
+  connection_ = connector->Connect("mojo:tracing");
   connection_->AddInterface(this);
 
 #ifdef NDEBUG
diff --git a/mojo/services/tracing/public/cpp/tracing_impl.h b/mojo/services/tracing/public/cpp/tracing_impl.h
index 42d0a74..a4e82ab 100644
--- a/mojo/services/tracing/public/cpp/tracing_impl.h
+++ b/mojo/services/tracing/public/cpp/tracing_impl.h
@@ -13,7 +13,7 @@
 namespace mojo {
 
 class Connection;
-class Shell;
+class Connector;
 
 // Connects to mojo:tracing during your Application's Initialize() call once
 // per process.
@@ -32,7 +32,7 @@ class TracingImpl : public InterfaceFactory<tracing::TraceProvider> {
 
   // This connects to the tracing service and registers ourselves to provide
   // tracing data on demand.
-  void Initialize(Shell* shell, const std::string& url);
+  void Initialize(Connector* connector, const std::string& url);
 
  private:
   // InterfaceFactory<tracing::TraceProvider> implementation.
diff --git a/mojo/services/tracing/tracing_app.cc b/mojo/services/tracing/tracing_app.cc
index 974ce0d..f7885eb 100644
--- a/mojo/services/tracing/tracing_app.cc
+++ b/mojo/services/tracing/tracing_app.cc
@@ -42,6 +42,11 @@ bool TracingApp::AcceptConnection(mojo::Connection* connection) {
   return true;
 }
 
+bool TracingApp::ShellConnectionLost() {
+  base::MessageLoop::current()->QuitWhenIdle();
+  return true;
+}
+
 void TracingApp::Create(mojo::Connection* connection,
                         mojo::InterfaceRequest<TraceCollector> request) {
   collector_binding_.Bind(std::move(request));
diff --git a/mojo/services/tracing/tracing_app.h b/mojo/services/tracing/tracing_app.h
index f409887..eb5934a 100644
--- a/mojo/services/tracing/tracing_app.h
+++ b/mojo/services/tracing/tracing_app.h
@@ -34,6 +34,7 @@ class TracingApp
  private:
   // mojo::ShellClient implementation.
   bool AcceptConnection(mojo::Connection* connection) override;
+  bool ShellConnectionLost() override;
 
   // mojo::InterfaceFactory<TraceCollector> implementation.
   void Create(mojo::Connection* connection,
diff --git a/mojo/shell/background/tests/background_shell_unittest.cc b/mojo/shell/background/tests/background_shell_unittest.cc
index 19280ef..79be067 100644
--- a/mojo/shell/background/tests/background_shell_unittest.cc
+++ b/mojo/shell/background/tests/background_shell_unittest.cc
@@ -7,6 +7,7 @@
 #include "base/run_loop.h"
 #include "mojo/shell/background/tests/test.mojom.h"
 #include "mojo/shell/background/tests/test_application_catalog_store.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/cpp/shell_connection.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -55,8 +56,8 @@ TEST(BackgroundShellTest, DISABLED_Basic) {
       &shell_client, background_shell.CreateShellClientRequest(GURL(kTestUrl)));
   shell_connection.WaitForInitialize();
   mojom::TestServicePtr test_service;
-  static_cast<Shell*>(&shell_connection)
-      ->ConnectToInterface("mojo:background_shell_test_app", &test_service);
+  shell_connection.connector()->ConnectToInterface(
+      "mojo:background_shell_test_app", &test_service);
   base::RunLoop run_loop;
   bool got_result = false;
   test_service->Test([&run_loop, &got_result]() {
diff --git a/mojo/shell/background/tests/test_service.cc b/mojo/shell/background/tests/test_service.cc
index 4d001af..8b68c59 100644
--- a/mojo/shell/background/tests/test_service.cc
+++ b/mojo/shell/background/tests/test_service.cc
@@ -21,10 +21,6 @@ class TestClient : public ShellClient,
 
  private:
   // ShellClient:
-  void Initialize(Shell* shell,
-                  const std::string& url,
-                  uint32_t id,
-                  uint32_t user_id) override {}
   bool AcceptConnection(Connection* connection) override {
     connection->AddInterface(this);
     return true;
diff --git a/mojo/shell/public/cpp/BUILD.gn b/mojo/shell/public/cpp/BUILD.gn
index 1ad6892..e4342c9 100644
--- a/mojo/shell/public/cpp/BUILD.gn
+++ b/mojo/shell/public/cpp/BUILD.gn
@@ -36,8 +36,10 @@ source_set("sources") {
     "lib/connector_impl.h",
     "lib/interface_factory_binder.h",
     "lib/interface_registry.cc",
+    "lib/message_loop_ref.cc",
     "lib/shell_client.cc",
     "lib/shell_connection.cc",
+    "message_loop_ref.h",
     "shell.h",
     "shell_client.h",
     "shell_connection.h",
diff --git a/mojo/shell/public/cpp/application_test_base.h b/mojo/shell/public/cpp/application_test_base.h
index f8ff6ad..bba5916 100644
--- a/mojo/shell/public/cpp/application_test_base.h
+++ b/mojo/shell/public/cpp/application_test_base.h
@@ -9,6 +9,7 @@
 #include "mojo/public/cpp/bindings/array.h"
 #include "mojo/public/cpp/bindings/string.h"
 #include "mojo/public/cpp/system/macros.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/cpp/shell_connection.h"
 #include "mojo/shell/public/interfaces/shell_client.mojom.h"
@@ -32,8 +33,8 @@ class TestHelper {
   explicit TestHelper(ShellClient* client);
   ~TestHelper();
 
-  Shell* shell() { return shell_connection_.get(); }
-  std::string shell_url() { return url_; }
+  Connector* connector() { return shell_connection_->connector(); }
+  std::string test_url() { return url_; }
 
  private:
   // The application delegate used if GetShellClient is not overridden.
@@ -54,11 +55,11 @@ class ApplicationTestBase : public testing::Test {
   ~ApplicationTestBase() override;
 
  protected:
-  Shell* shell() {
-    return test_helper_ ? test_helper_->shell() : nullptr;
+  Connector* connector() {
+    return test_helper_ ? test_helper_->connector() : nullptr;
   }
-  std::string shell_url() const {
-    return test_helper_ ? test_helper_->shell_url() : std::string();
+  std::string test_url() const {
+    return test_helper_ ? test_helper_->test_url() : std::string();
   }
 
   // Get the ShellClient for the application to be tested.
diff --git a/mojo/shell/public/cpp/lib/message_loop_ref.cc b/mojo/shell/public/cpp/lib/message_loop_ref.cc
new file mode 100644
index 0000000..a285cda
--- /dev/null
+++ b/mojo/shell/public/cpp/lib/message_loop_ref.cc
@@ -0,0 +1,98 @@
+// 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 "mojo/shell/public/cpp/message_loop_ref.h"
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+
+namespace mojo {
+
+class MessageLoopRefImpl : public MessageLoopRef {
+ public:
+  MessageLoopRefImpl(
+      MessageLoopRefFactory* factory,
+      scoped_refptr<base::SingleThreadTaskRunner> app_task_runner)
+      : factory_(factory),
+        app_task_runner_(app_task_runner) {}
+  ~MessageLoopRefImpl() override {
+#ifndef NDEBUG
+    // Ensure that this object is used on only one thread at a time, or else
+    // there could be races where the object is being reset on one thread and
+    // cloned on another.
+    if (clone_task_runner_)
+      DCHECK(clone_task_runner_->BelongsToCurrentThread());
+#endif
+
+    if (app_task_runner_->BelongsToCurrentThread()) {
+      factory_->Release();
+    } else {
+      app_task_runner_->PostTask(
+          FROM_HERE,
+          base::Bind(&MessageLoopRefFactory::Release,
+                     base::Unretained(factory_)));
+    }
+  }
+
+ private:
+  // MessageLoopRef:
+  scoped_ptr<MessageLoopRef> Clone() override {
+    if (app_task_runner_->BelongsToCurrentThread()) {
+      factory_->AddRef();
+    } else {
+      app_task_runner_->PostTask(
+          FROM_HERE,
+          base::Bind(&MessageLoopRefFactory::AddRef,
+                     base::Unretained(factory_)));
+    }
+
+#ifndef NDEBUG
+    // Ensure that this object is used on only one thread at a time, or else
+    // there could be races where the object is being reset on one thread and
+    // cloned on another.
+    if (clone_task_runner_) {
+      DCHECK(clone_task_runner_->BelongsToCurrentThread());
+    } else {
+      clone_task_runner_ = base::MessageLoop::current()->task_runner();
+    }
+#endif
+
+    return make_scoped_ptr(new MessageLoopRefImpl(factory_, app_task_runner_));
+  }
+
+  MessageLoopRefFactory* factory_;
+  scoped_refptr<base::SingleThreadTaskRunner> app_task_runner_;
+
+#ifndef NDEBUG
+  scoped_refptr<base::SingleThreadTaskRunner> clone_task_runner_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(MessageLoopRefImpl);
+};
+
+MessageLoopRefFactory::MessageLoopRefFactory() {}
+MessageLoopRefFactory::~MessageLoopRefFactory() {}
+
+scoped_ptr<MessageLoopRef> MessageLoopRefFactory::CreateRef() {
+  AddRef();
+  return make_scoped_ptr(new MessageLoopRefImpl(
+      this, base::MessageLoop::current()->task_runner()));
+}
+
+void MessageLoopRefFactory::AddRef() {
+  ++ref_count_;
+}
+
+void MessageLoopRefFactory::Release() {
+  if (!--ref_count_) {
+    if (!quit_closure_.is_null())
+      quit_closure_.Run();
+    if (base::MessageLoop::current() &&
+        base::MessageLoop::current()->is_running()) {
+      base::MessageLoop::current()->QuitWhenIdle();
+    }
+  }
+}
+
+}  // namespace mojo
diff --git a/mojo/shell/public/cpp/lib/shell_client.cc b/mojo/shell/public/cpp/lib/shell_client.cc
index 6570068..0d553f0 100644
--- a/mojo/shell/public/cpp/lib/shell_client.cc
+++ b/mojo/shell/public/cpp/lib/shell_client.cc
@@ -9,7 +9,7 @@ namespace mojo {
 ShellClient::ShellClient() {}
 ShellClient::~ShellClient() {}
 
-void ShellClient::Initialize(Shell* app, const std::string& url,
+void ShellClient::Initialize(Connector* connector, const std::string& url,
                              uint32_t id, uint32_t user_id) {
 }
 
@@ -21,6 +21,4 @@ bool ShellClient::ShellConnectionLost() {
   return true;
 }
 
-void ShellClient::Quit() {}
-
 }  // namespace mojo
diff --git a/mojo/shell/public/cpp/lib/shell_connection.cc b/mojo/shell/public/cpp/lib/shell_connection.cc
index e14cc77..5977cc6 100644
--- a/mojo/shell/public/cpp/lib/shell_connection.cc
+++ b/mojo/shell/public/cpp/lib/shell_connection.cc
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <algorithm>
-#include <utility>
-
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ -17,65 +14,6 @@
 
 namespace mojo {
 
-class AppRefCountImpl : public AppRefCount {
- public:
-  AppRefCountImpl(ShellConnection* connection,
-                  scoped_refptr<base::SingleThreadTaskRunner> app_task_runner)
-      : connection_(connection),
-        app_task_runner_(app_task_runner) {}
-  ~AppRefCountImpl() override {
-#ifndef NDEBUG
-    // Ensure that this object is used on only one thread at a time, or else
-    // there could be races where the object is being reset on one thread and
-    // cloned on another.
-    if (clone_task_runner_)
-      DCHECK(clone_task_runner_->BelongsToCurrentThread());
-#endif
-
-    if (app_task_runner_->BelongsToCurrentThread()) {
-      connection_->Release();
-    } else {
-      app_task_runner_->PostTask(
-          FROM_HERE,
-          base::Bind(&ShellConnection::Release, base::Unretained(connection_)));
-    }
-  }
-
- private:
-  // AppRefCount:
-  scoped_ptr<AppRefCount> Clone() override {
-    if (app_task_runner_->BelongsToCurrentThread()) {
-      connection_->AddRef();
-    } else {
-      app_task_runner_->PostTask(
-          FROM_HERE,
-          base::Bind(&ShellConnection::AddRef, base::Unretained(connection_)));
-    }
-
-#ifndef NDEBUG
-    // Ensure that this object is used on only one thread at a time, or else
-    // there could be races where the object is being reset on one thread and
-    // cloned on another.
-    if (clone_task_runner_) {
-      DCHECK(clone_task_runner_->BelongsToCurrentThread());
-    } else {
-      clone_task_runner_ = base::MessageLoop::current()->task_runner();
-    }
-#endif
-
-    return make_scoped_ptr(new AppRefCountImpl(connection_, app_task_runner_));
-  }
-
-  ShellConnection* connection_;
-  scoped_refptr<base::SingleThreadTaskRunner> app_task_runner_;
-
-#ifndef NDEBUG
-  scoped_refptr<base::SingleThreadTaskRunner> clone_task_runner_;
-#endif
-
-  DISALLOW_COPY_AND_ASSIGN(AppRefCountImpl);
-};
-
 ////////////////////////////////////////////////////////////////////////////////
 // ShellConnection, public:
 
@@ -84,7 +22,6 @@ ShellConnection::ShellConnection(
     InterfaceRequest<shell::mojom::ShellClient> request)
     : client_(client),
       binding_(this, std::move(request)),
-      ref_count_(0),
       weak_factory_(this) {}
 
 ShellConnection::~ShellConnection() {}
@@ -95,36 +32,6 @@ void ShellConnection::WaitForInitialize() {
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-// ShellConnection, Shell implementation:
-
-scoped_ptr<Connection> ShellConnection::Connect(const std::string& url) {
-  return connector_->Connect(url);
-}
-
-scoped_ptr<Connection> ShellConnection::Connect(
-    Connector::ConnectParams* params) {
-  return connector_->Connect(params);
-}
-
-scoped_ptr<Connector> ShellConnection::CloneConnector() const {
-  return connector_->Clone();
-}
-
-scoped_ptr<AppRefCount> ShellConnection::CreateAppRefCount() {
-  AddRef();
-  return make_scoped_ptr(
-      new AppRefCountImpl(this, base::MessageLoop::current()->task_runner()));
-}
-
-void ShellConnection::Quit() {
-  client_->Quit();
-  if (base::MessageLoop::current() &&
-      base::MessageLoop::current()->is_running()) {
-    base::MessageLoop::current()->QuitWhenIdle();
-  }
-}
-
-////////////////////////////////////////////////////////////////////////////////
 // ShellConnection, shell::mojom::ShellClient implementation:
 
 void ShellConnection::Initialize(shell::mojom::ConnectorPtr connector,
@@ -135,7 +42,7 @@ void ShellConnection::Initialize(shell::mojom::ConnectorPtr connector,
       std::move(connector),
       base::Bind(&ShellConnection::OnConnectionError,
                  weak_factory_.GetWeakPtr())));
-  client_->Initialize(this, url, id, user_id);
+  client_->Initialize(connector_.get(), url, id, user_id);
 }
 
 void ShellConnection::AcceptConnection(
@@ -162,27 +69,12 @@ void ShellConnection::AcceptConnection(
 // ShellConnection, private:
 
 void ShellConnection::OnConnectionError() {
-  base::WeakPtr<ShellConnection> ptr(weak_factory_.GetWeakPtr());
-
   // We give the client notice first, since it might want to do something on
   // shell connection errors other than immediate termination of the run
   // loop. The application might want to continue servicing connections other
   // than the one to the shell.
-  bool quit_now = client_->ShellConnectionLost();
-  if (quit_now)
-    Quit();
-  if (!ptr)
-    return;
-  connector_.reset();
-}
-
-void ShellConnection::AddRef() {
-  ++ref_count_;
-}
-
-void ShellConnection::Release() {
-  if (!--ref_count_)
-    Quit();
+  if (client_->ShellConnectionLost())
+    connector_.reset();
 }
 
 }  // namespace mojo
diff --git a/mojo/shell/public/cpp/message_loop_ref.h b/mojo/shell/public/cpp/message_loop_ref.h
new file mode 100644
index 0000000..fffb738
--- /dev/null
+++ b/mojo/shell/public/cpp/message_loop_ref.h
@@ -0,0 +1,57 @@
+// 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.
+
+#ifndef MOJO_SHELL_PUBLIC_CPP_APPLICATION_RUNNER_REFERENCE_H_
+#define MOJO_SHELL_PUBLIC_CPP_APPLICATION_RUNNER_REFERENCE_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "mojo/public/cpp/system/core.h"
+
+namespace mojo {
+
+class MessageLoopRefImpl;
+
+// An interface implementation can keep this object as a member variable to
+// hold a reference to the ShellConnection, keeping it alive as long as the
+// bound implementation exists.
+// Since interface implementations can be bound on different threads than the
+// ShellConnection, this class is safe to use on any thread. However, each
+// instance should only be used on one thread at a time (otherwise there'll be
+// races between the AddRef resulting from cloning and destruction).
+class MessageLoopRef {
+ public:
+  virtual ~MessageLoopRef() {}
+
+  virtual scoped_ptr<MessageLoopRef> Clone() = 0;
+};
+
+class MessageLoopRefFactory {
+ public:
+  MessageLoopRefFactory();
+  ~MessageLoopRefFactory();
+
+  void set_quit_closure(const base::Closure& quit_closure) {
+    quit_closure_ = quit_closure;
+  }
+
+  scoped_ptr<MessageLoopRef> CreateRef();
+
+ private:
+  friend MessageLoopRefImpl;
+
+  // Called from MessageLoopRefImpl.
+  void AddRef();
+  void Release();
+
+  base::Closure quit_closure_;
+  int ref_count_ = 0;
+
+  DISALLOW_COPY_AND_ASSIGN(MessageLoopRefFactory);
+};
+
+}  // namespace mojo
+
+#endif  // MOJO_SHELL_PUBLIC_CPP_APPLICATION_RUNNER_REFERENCE_H_
diff --git a/mojo/shell/public/cpp/shell.h b/mojo/shell/public/cpp/shell.h
index cade46a..772d23f 100644
--- a/mojo/shell/public/cpp/shell.h
+++ b/mojo/shell/public/cpp/shell.h
@@ -5,67 +5,11 @@
 #ifndef MOJO_SHELL_PUBLIC_CPP_SHELL_H_
 #define MOJO_SHELL_PUBLIC_CPP_SHELL_H_
 
-#include "mojo/shell/public/cpp/connection.h"
 #include "mojo/shell/public/cpp/connector.h"
-#include "mojo/shell/public/interfaces/shell.mojom.h"
-#include "url/gurl.h"
 
 namespace mojo {
 
-// An interface implementation can keep this object as a member variable to
-// hold a reference to the ShellConnection, keeping it alive as long as the
-// bound implementation exists.
-// Since interface implementations can be bound on different threads than the
-// ShellConnection, this class is safe to use on any thread. However, each
-// instance should only be used on one thread at a time (otherwise there'll be
-// races between the AddRef resulting from cloning and destruction).
-class AppRefCount {
- public:
-  virtual ~AppRefCount() {}
-
-  virtual scoped_ptr<AppRefCount> Clone() = 0;
-};
-
-// An interface that encapsulates the Mojo Shell's broker interface by which
-// connections between applications are established. Implemented by
-// ShellConnection, this is the primary interface exposed to clients.
-class Shell {
- public:
-  // Requests a new connection to an application. Returns a pointer to the
-  // connection if the connection is permitted by this application's delegate,
-  // or nullptr otherwise. Caller takes ownership.
-  virtual scoped_ptr<Connection> Connect(const std::string& url) = 0;
-  virtual scoped_ptr<Connection> Connect(Connector::ConnectParams* params) = 0;
-
-  // Connect to application identified by |request->url| and connect to the
-  // service implementation of the interface identified by |Interface|.
-  template <typename Interface>
-  void ConnectToInterface(Connector::ConnectParams* params,
-                          InterfacePtr<Interface>* ptr) {
-    scoped_ptr<Connection> connection = Connect(params);
-    if (connection)
-      connection->GetInterface(ptr);
-  }
-  template <typename Interface>
-  void ConnectToInterface(const std::string& url,
-                          InterfacePtr<Interface>* ptr) {
-    Connector::ConnectParams params(url);
-    return ConnectToInterface(&params, ptr);
-  }
-
-  // Returns a clone of the ShellConnection's Connector that can be passed to
-  // other threads.
-  virtual scoped_ptr<Connector> CloneConnector() const = 0;
-
-  // Quits the message loop run by the ApplicationRunner, which causes this
-  // object to be destructed and the application to quit.
-  virtual void Quit() = 0;
-
-  // Create an object that can be used to refcount the lifetime of the
-  // application. The returned object may be cloned, and when the refcount falls
-  // to zero Quit() is called.
-  virtual scoped_ptr<AppRefCount> CreateAppRefCount() = 0;
-};
+using Shell = Connector;
 
 }  // namespace mojo
 
diff --git a/mojo/shell/public/cpp/shell_client.h b/mojo/shell/public/cpp/shell_client.h
index b7a8e0e..0d6fde1 100644
--- a/mojo/shell/public/cpp/shell_client.h
+++ b/mojo/shell/public/cpp/shell_client.h
@@ -13,7 +13,7 @@
 
 namespace mojo {
 
-class Shell;
+class Connector;
 
 // An interface representing an instance "known to the Mojo Shell". The
 // implementation receives lifecycle messages for the instance and gets the
@@ -31,7 +31,7 @@ class ShellClient {
   // instance of the application.
   // |user_id| identifies the user this instance is run as.
   // Called exactly once before any other method.
-  virtual void Initialize(Shell* shell,
+  virtual void Initialize(Connector* connector,
                           const std::string& url,
                           uint32_t id,
                           uint32_t user_id = 0);
@@ -44,20 +44,10 @@ class ShellClient {
 
   // Called when ShellConnection's pipe to the Mojo Shell is closed.
   //
-  // Returning true from this method will cause the ShellConnection instance to
-  // call this instance back via Quit(), and then run the termination closure
-  // passed to it (which may do cleanup like, for example, quitting a run loop).
-  // Returning false from this method will not do any of this. The client is
-  // then responsible for calling Shell::QuitNow() when it is ready to close.
-  // The client may do this if it wishes to continue servicing connections other
-  // than the Shell.
+  // Returning true from this method will cause ...
   // The default implementation returns true.
   virtual bool ShellConnectionLost();
 
-  // Called before ShellConnection::QuitNow(). After returning from this call
-  // the delegate can no longer rely on the main run loop still running.
-  virtual void Quit();
-
  private:
   MOJO_DISALLOW_COPY_AND_ASSIGN(ShellClient);
 };
diff --git a/mojo/shell/public/cpp/shell_connection.h b/mojo/shell/public/cpp/shell_connection.h
index d79b788..123bd93 100644
--- a/mojo/shell/public/cpp/shell_connection.h
+++ b/mojo/shell/public/cpp/shell_connection.h
@@ -14,14 +14,12 @@
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/cpp/bindings/callback.h"
 #include "mojo/public/cpp/system/core.h"
-#include "mojo/shell/public/cpp/shell.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/interfaces/shell.mojom.h"
 #include "mojo/shell/public/interfaces/shell_client.mojom.h"
 
 namespace mojo {
 
-class AppRefCountImpl;
 class Connector;
 
 // Encapsulates a connection to the Mojo Shell in two parts:
@@ -44,10 +42,7 @@ class Connector;
 // Client Lib's mojo::ShellClient interface. See documentation in shell_client.h
 // for details.
 //
-// Though this class provides the canonical implementation of the Shell Client
-// lib's mojo::Shell interface, this interface should not be reached through
-// pointers to this type.
-class ShellConnection : public Shell, public shell::mojom::ShellClient {
+class ShellConnection : public shell::mojom::ShellClient {
  public:
   // Does not take ownership of |delegate|, which must remain valid for the
   // lifetime of ShellConnection.
@@ -59,16 +54,9 @@ class ShellConnection : public Shell, public shell::mojom::ShellClient {
   // shell.
   void WaitForInitialize();
 
- private:
-  friend AppRefCountImpl;
-
-  // Shell:
-  scoped_ptr<Connection> Connect(const std::string& url) override;
-  scoped_ptr<Connection> Connect(Connector::ConnectParams* params) override;
-  scoped_ptr<Connector> CloneConnector() const override;
-  scoped_ptr<AppRefCount> CreateAppRefCount() override;
-  void Quit() override;
+  Connector* connector() { return connector_.get(); }
 
+ private:
   // shell::mojom::ShellClient:
   void Initialize(shell::mojom::ConnectorPtr connector,
                   const mojo::String& url,
@@ -85,17 +73,12 @@ class ShellConnection : public Shell, public shell::mojom::ShellClient {
 
   void OnConnectionError();
 
-  // Called from AppRefCountImpl.
-  void AddRef();
-  void Release();
-
   // We track the lifetime of incoming connection registries as it more
   // convenient for the client.
   ScopedVector<Connection> incoming_connections_;
   mojo::ShellClient* client_;
   Binding<shell::mojom::ShellClient> binding_;
   scoped_ptr<Connector> connector_;
-  int ref_count_;
   base::WeakPtrFactory<ShellConnection> weak_factory_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(ShellConnection);
diff --git a/mojo/shell/runner/child/native_apptest.cc b/mojo/shell/runner/child/native_apptest.cc
index 7368fbc..d0ab0b7 100644
--- a/mojo/shell/runner/child/native_apptest.cc
+++ b/mojo/shell/runner/child/native_apptest.cc
@@ -19,8 +19,8 @@ using NativeAppTest = mojo::test::ApplicationTestBase;
 
 TEST_F(NativeAppTest, Connect) {
   test::TestNativeServicePtr native_service;
-  shell()->ConnectToInterface("exe:mojo_runner_child_apptest_native_target",
-                              &native_service);
+  connector()->ConnectToInterface("exe:mojo_runner_child_apptest_native_target",
+                                  &native_service);
 
   bool result = false;
   native_service->Invert(
diff --git a/mojo/shell/runner/child/native_apptest_target.cc b/mojo/shell/runner/child/native_apptest_target.cc
index 04ebdbb..565ba30 100644
--- a/mojo/shell/runner/child/native_apptest_target.cc
+++ b/mojo/shell/runner/child/native_apptest_target.cc
@@ -10,7 +10,6 @@
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/shell/public/cpp/connection.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
-#include "mojo/shell/public/cpp/shell.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/runner/child/test_native_main.h"
 #include "mojo/shell/runner/child/test_native_service.mojom.h"
@@ -28,8 +27,6 @@ class TargetApplicationDelegate
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
-                  uint32_t id, uint32_t user_id) override {}
   bool AcceptConnection(mojo::Connection* connection) override {
     connection->AddInterface<mojo::shell::test::TestNativeService>(this);
     return true;
diff --git a/mojo/shell/tests/application_manager_apptest.cc b/mojo/shell/tests/application_manager_apptest.cc
index 82fa8bc..a848611 100644
--- a/mojo/shell/tests/application_manager_apptest.cc
+++ b/mojo/shell/tests/application_manager_apptest.cc
@@ -14,7 +14,7 @@
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/shell/public/cpp/application_test_base.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/interfaces/application_manager.mojom.h"
 #include "mojo/shell/tests/application_manager_apptests.mojom.h"
 
@@ -38,8 +38,6 @@ class ApplicationManagerAppTestDelegate
 
  private:
   // mojo::ShellClient:
-  void Initialize(Shell* shell, const std::string& url, uint32_t id,
-                  uint32_t user_id) override {}
   bool AcceptConnection(Connection* connection) override {
     connection->AddInterface<CreateInstanceForHandleTest>(this);
     return true;
@@ -88,7 +86,7 @@ class ApplicationManagerAppTest : public mojo::test::ApplicationTestBase,
 
   void AddListenerAndWaitForApplications() {
     mojom::ApplicationManagerPtr application_manager;
-    shell()->ConnectToInterface("mojo:shell", &application_manager);
+    connector()->ConnectToInterface("mojo:shell", &application_manager);
 
     application_manager->AddListener(binding_.CreateInterfacePtrAndBind());
     binding_.WaitForIncomingMethodCall();
@@ -169,7 +167,7 @@ TEST_F(ApplicationManagerAppTest, CreateInstanceForHandle) {
   //    launches a process. #becauselinkerrors).
   mojo::shell::test::mojom::DriverPtr driver;
   scoped_ptr<Connection> connection =
-      shell()->Connect("exe:application_manager_apptest_driver");
+      connector()->Connect("exe:application_manager_apptest_driver");
   connection->GetInterface(&driver);
 
   // 2. Wait for the target to connect to us. (via
diff --git a/mojo/shell/tests/application_manager_apptest_driver.cc b/mojo/shell/tests/application_manager_apptest_driver.cc
index 2a820fe..7342d72 100644
--- a/mojo/shell/tests/application_manager_apptest_driver.cc
+++ b/mojo/shell/tests/application_manager_apptest_driver.cc
@@ -23,8 +23,8 @@
 #include "mojo/edk/embedder/scoped_platform_handle.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/shell/public/cpp/connection.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
-#include "mojo/shell/public/cpp/shell.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/interfaces/application_manager.mojom.h"
 #include "mojo/shell/runner/child/test_native_main.h"
@@ -41,15 +41,13 @@ class TargetApplicationDelegate : public mojo::ShellClient,
                                   public mojo::InterfaceFactory<Driver>,
                                   public Driver {
  public:
-  TargetApplicationDelegate() : shell_(nullptr), weak_factory_(this) {}
+  TargetApplicationDelegate() : weak_factory_(this) {}
   ~TargetApplicationDelegate() override {}
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override {
-    shell_ = shell;
-
     base::FilePath target_path;
     CHECK(base::PathService::Get(base::DIR_EXE, &target_path));
   #if defined(OS_WIN)
@@ -98,7 +96,7 @@ class TargetApplicationDelegate : public mojo::ShellClient,
                           std::move(test_interfaces));
 
     mojo::shell::mojom::ApplicationManagerPtr application_manager;
-    shell_->ConnectToInterface("mojo:shell", &application_manager);
+    connector->ConnectToInterface("mojo:shell", &application_manager);
     application_manager->CreateInstanceForHandle(
         mojo::ScopedHandle(mojo::Handle(pipe.release().value())),
         "exe:application_manager_apptest_target", std::move(filter),
@@ -131,10 +129,9 @@ class TargetApplicationDelegate : public mojo::ShellClient,
   // Driver:
   void QuitDriver() override {
     target_.Terminate(0, false);
-    shell_->Quit();
+    base::MessageLoop::current()->QuitWhenIdle();
   }
 
-  mojo::Shell* shell_;
   base::Process target_;
   mojo::BindingSet<Driver> bindings_;
   base::WeakPtrFactory<TargetApplicationDelegate> weak_factory_;
diff --git a/mojo/shell/tests/application_manager_apptest_target.cc b/mojo/shell/tests/application_manager_apptest_target.cc
index 5284553..0c36d10 100644
--- a/mojo/shell/tests/application_manager_apptest_target.cc
+++ b/mojo/shell/tests/application_manager_apptest_target.cc
@@ -6,7 +6,7 @@
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/runner/child/test_native_main.h"
 #include "mojo/shell/runner/init.h"
@@ -23,10 +23,10 @@ class TargetApplicationDelegate : public mojo::ShellClient {
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Shell* shell, const std::string& url,
+  void Initialize(mojo::Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override {
     CreateInstanceForHandleTestPtr service;
-    shell->ConnectToInterface("mojo:mojo_shell_apptests", &service);
+    connector->ConnectToInterface("mojo:mojo_shell_apptests", &service);
     service->SetTargetID(id);
   }
 
diff --git a/mojo/shell/tests/application_manager_unittest.cc b/mojo/shell/tests/application_manager_unittest.cc
index 51bcc15..bed3c74 100644
--- a/mojo/shell/tests/application_manager_unittest.cc
+++ b/mojo/shell/tests/application_manager_unittest.cc
@@ -16,6 +16,7 @@
 #include "mojo/services/package_manager/package_manager.h"
 #include "mojo/shell/application_loader.h"
 #include "mojo/shell/connect_util.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/cpp/shell_connection.h"
@@ -245,12 +246,12 @@ class TesterContext {
 // Used to test that the requestor url will be correctly passed.
 class TestAImpl : public TestA {
  public:
-  TestAImpl(Shell* shell,
+  TestAImpl(Connector* connector,
             TesterContext* test_context,
             InterfaceRequest<TestA> request,
             InterfaceFactory<TestC>* factory)
       : test_context_(test_context), binding_(this, std::move(request)) {
-    connection_ = shell->Connect(kTestBURLString);
+    connection_ = connector->Connect(kTestBURLString);
     connection_->AddInterface<TestC>(factory);
     connection_->GetInterface(&b_);
   }
@@ -368,7 +369,7 @@ class Tester : public ShellClient,
   void Create(Connection* connection,
               InterfaceRequest<TestA> request) override {
     a_bindings_.push_back(
-        new TestAImpl(app_.get(), context_, std::move(request), this));
+        new TestAImpl(app_->connector(), context_, std::move(request), this));
   }
 
   void Create(Connection* connection,
diff --git a/mojo/shell/tests/capability_filter_test.cc b/mojo/shell/tests/capability_filter_test.cc
index 3fac67c..1c3a1fa 100644
--- a/mojo/shell/tests/capability_filter_test.cc
+++ b/mojo/shell/tests/capability_filter_test.cc
@@ -14,6 +14,7 @@
 #include "mojo/services/package_manager/package_manager.h"
 #include "mojo/shell/application_loader.h"
 #include "mojo/shell/public/cpp/connection.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
 #include "mojo/shell/public/cpp/shell_connection.h"
 
@@ -111,17 +112,16 @@ class ServiceApplication : public ShellClient,
                            public Safe,
                            public Unsafe {
  public:
-  ServiceApplication() : shell_(nullptr) {}
+  ServiceApplication() {}
   ~ServiceApplication() override {}
 
  private:
   // Overridden from ShellClient:
-  void Initialize(Shell* shell, const std::string& url, uint32_t id,
+  void Initialize(Connector* connector, const std::string& url, uint32_t id,
                   uint32_t user_id) override {
-    shell_ = shell;
     // ServiceApplications have no capability filter and can thus connect
     // directly to the validator application.
-    shell_->ConnectToInterface("test:validator", &validator_);
+    connector->ConnectToInterface("test:validator", &validator_);
   }
   bool AcceptConnection(Connection* connection) override {
     AddInterface<Safe>(connection);
@@ -149,7 +149,6 @@ class ServiceApplication : public ShellClient,
                                    !connection->AddInterface<Interface>(this));
   }
 
-  Shell* shell_;
   ValidatorPtr validator_;
   BindingSet<Safe> safe_bindings_;
   BindingSet<Unsafe> unsafe_bindings_;
@@ -160,24 +159,24 @@ class ServiceApplication : public ShellClient,
 ////////////////////////////////////////////////////////////////////////////////
 // TestApplication:
 
-TestApplication::TestApplication() : shell_(nullptr) {}
+TestApplication::TestApplication() : connector_(nullptr) {}
 TestApplication::~TestApplication() {}
 
-void TestApplication::Initialize(Shell* shell, const std::string& url,
+void TestApplication::Initialize(Connector* connector, const std::string& url,
                                  uint32_t id, uint32_t user_id) {
-  shell_ = shell;
+  connector_ = connector;
   url_ = url;
 }
 bool TestApplication::AcceptConnection(Connection* connection) {
   // TestApplications receive their Validator via the inbound connection.
   connection->GetInterface(&validator_);
 
-  connection1_ = shell_->Connect("test:service");
+  connection1_ = connector_->Connect("test:service");
   connection1_->SetRemoteInterfaceProviderConnectionErrorHandler(
       base::Bind(&TestApplication::ConnectionClosed,
                   base::Unretained(this), "test:service"));
 
-  connection2_ = shell_->Connect("test:service2");
+  connection2_ = connector_->Connect("test:service2");
   connection2_->SetRemoteInterfaceProviderConnectionErrorHandler(
       base::Bind(&TestApplication::ConnectionClosed,
                   base::Unretained(this), "test:service2"));
diff --git a/mojo/shell/tests/capability_filter_test.h b/mojo/shell/tests/capability_filter_test.h
index 45a5fa8..43d7e47 100644
--- a/mojo/shell/tests/capability_filter_test.h
+++ b/mojo/shell/tests/capability_filter_test.h
@@ -29,13 +29,13 @@ class TestApplication : public ShellClient {
 
  private:
   // Overridden from ShellClient:
-  void Initialize(Shell* shell, const std::string& url, uint32_t id,
+  void Initialize(Connector* connector, const std::string& url, uint32_t id,
                   uint32_t user_id) override;
   bool AcceptConnection(Connection* connection) override;
 
   void ConnectionClosed(const std::string& service_url);
 
-  Shell* shell_;
+  Connector* connector_;
   std::string url_;
   ValidatorPtr validator_;
   scoped_ptr<Connection> connection1_;
diff --git a/mojo/shell/tests/package_apptest.cc b/mojo/shell/tests/package_apptest.cc
index ecdb0d9..8b739ad 100644
--- a/mojo/shell/tests/package_apptest.cc
+++ b/mojo/shell/tests/package_apptest.cc
@@ -38,7 +38,7 @@ TEST_F(PackageApptest, Basic) {
     // register aliases.
     test::mojom::PackageTestServicePtr root_service;
     scoped_ptr<Connection> connection =
-        shell()->Connect("mojo:package_test_package");
+        connector()->Connect("mojo:package_test_package");
     connection->GetInterface(&root_service);
     base::RunLoop run_loop;
     std::string root_name;
@@ -53,7 +53,8 @@ TEST_F(PackageApptest, Basic) {
     // Now subsequent connects to applications provided by the root app will be
     // resolved correctly.
     test::mojom::PackageTestServicePtr service_a;
-    scoped_ptr<Connection> connection = shell()->Connect("mojo:package_test_a");
+    scoped_ptr<Connection> connection =
+        connector()->Connect("mojo:package_test_a");
     connection->GetInterface(&service_a);
     base::RunLoop run_loop;
     std::string a_name;
@@ -67,7 +68,8 @@ TEST_F(PackageApptest, Basic) {
 
   {
     test::mojom::PackageTestServicePtr service_b;
-    scoped_ptr<Connection> connection = shell()->Connect("mojo:package_test_b");
+    scoped_ptr<Connection> connection =
+        connector()->Connect("mojo:package_test_b");
     connection->GetInterface(&service_b);
     base::RunLoop run_loop;
     std::string b_name;
diff --git a/mojo/shell/tests/package_test_package.cc b/mojo/shell/tests/package_test_package.cc
index ee8ff5b..f25abd5 100644
--- a/mojo/shell/tests/package_test_package.cc
+++ b/mojo/shell/tests/package_test_package.cc
@@ -9,13 +9,13 @@
 
 #include "base/bind.h"
 #include "base/macros.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/threading/simple_thread.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/shell/public/cpp/application_runner.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
-#include "mojo/shell/public/cpp/shell.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/interfaces/shell_client_factory.mojom.h"
 #include "mojo/shell/tests/package_test.mojom.h"
@@ -39,8 +39,7 @@ class ProvidedShellClient
                       mojom::ShellClientRequest request)
       : base::SimpleThread(name),
         name_(name),
-        request_(std::move(request)),
-        shell_(nullptr) {
+        request_(std::move(request)) {
     Start();
   }
   ~ProvidedShellClient() override {
@@ -49,9 +48,8 @@ class ProvidedShellClient
 
  private:
   // mojo::ShellClient:
-  void Initialize(Shell* shell, const std::string& url,
+  void Initialize(Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override {
-    shell_ = shell;
     bindings_.set_connection_error_handler(
         base::Bind(&ProvidedShellClient::OnConnectionError,
                    base::Unretained(this)));
@@ -82,12 +80,11 @@ class ProvidedShellClient
 
   void OnConnectionError() {
     if (bindings_.empty())
-      shell_->Quit();
+      base::MessageLoop::current()->QuitWhenIdle();
   }
 
   const std::string name_;
   mojom::ShellClientRequest request_;
-  Shell* shell_;
   BindingSet<test::mojom::PackageTestService> bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(ProvidedShellClient);
@@ -100,14 +97,13 @@ class PackageTestShellClient
       public mojom::ShellClientFactory,
       public test::mojom::PackageTestService {
  public:
-  PackageTestShellClient() : shell_(nullptr) {}
+  PackageTestShellClient() {}
   ~PackageTestShellClient() override {}
 
  private:
   // mojo::ShellClient:
-  void Initialize(Shell* shell, const std::string& url,
+  void Initialize(Connector* connector, const std::string& url,
                   uint32_t id, uint32_t user_id) override {
-    shell_ = shell;
     bindings_.set_connection_error_handler(
         base::Bind(&PackageTestShellClient::OnConnectionError,
                    base::Unretained(this)));
@@ -117,6 +113,13 @@ class PackageTestShellClient
     connection->AddInterface<test::mojom::PackageTestService>(this);
     return true;
   }
+  bool ShellConnectionLost() override {
+    if (base::MessageLoop::current() &&
+        base::MessageLoop::current()->is_running()) {
+      base::MessageLoop::current()->QuitWhenIdle();
+    }
+    return true;
+  }
 
   // InterfaceFactory<mojom::ShellClientFactory>:
   void Create(Connection* connection,
@@ -146,10 +149,9 @@ class PackageTestShellClient
 
   void OnConnectionError() {
     if (bindings_.empty())
-      shell_->Quit();
+      base::MessageLoop::current()->QuitWhenIdle();
   }
 
-  Shell* shell_;
   std::vector<scoped_ptr<ShellClient>> delegates_;
   BindingSet<mojom::ShellClientFactory> shell_client_factory_bindings_;
   BindingSet<test::mojom::PackageTestService> bindings_;
diff --git a/ui/views/mus/aura_init.cc b/ui/views/mus/aura_init.cc
index bc4d98e..2b08108 100644
--- a/ui/views/mus/aura_init.cc
+++ b/ui/views/mus/aura_init.cc
@@ -11,7 +11,7 @@
 #include "base/path_service.h"
 #include "build/build_config.h"
 #include "components/resource_provider/public/cpp/resource_loader.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/aura/env.h"
 #include "ui/base/ime/input_method_initializer.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -50,12 +50,12 @@ class MusViewsDelegate : public ViewsDelegate {
 
 }  // namespace
 
-AuraInit::AuraInit(mojo::Shell* shell, const std::string& resource_file)
+AuraInit::AuraInit(mojo::Connector* connector, const std::string& resource_file)
     : resource_file_(resource_file),
       views_delegate_(new MusViewsDelegate) {
   aura::Env::CreateInstance(false);
 
-  InitializeResources(shell);
+  InitializeResources(connector);
 
   ui::InitializeInputMethodForTesting();
 }
@@ -72,11 +72,11 @@ AuraInit::~AuraInit() {
 #endif
 }
 
-void AuraInit::InitializeResources(mojo::Shell* shell) {
+void AuraInit::InitializeResources(mojo::Connector* connector) {
   if (ui::ResourceBundle::HasSharedInstance())
     return;
   resource_provider::ResourceLoader resource_loader(
-      shell, GetResourcePaths(resource_file_));
+      connector, GetResourcePaths(resource_file_));
   CHECK(resource_loader.BlockUntilLoaded());
   CHECK(resource_loader.loaded());
   ui::RegisterPathProvider();
@@ -89,7 +89,7 @@ void AuraInit::InitializeResources(mojo::Shell* shell) {
 
 // Initialize the skia font code to go ask fontconfig underneath.
 #if defined(OS_LINUX) && !defined(OS_ANDROID)
-  font_loader_ = skia::AdoptRef(new font_service::FontLoader(shell));
+  font_loader_ = skia::AdoptRef(new font_service::FontLoader(connector));
   SkFontConfigInterface::SetGlobal(font_loader_.get());
 #endif
 
diff --git a/ui/views/mus/aura_init.h b/ui/views/mus/aura_init.h
index b2cf750..521acac 100644
--- a/ui/views/mus/aura_init.h
+++ b/ui/views/mus/aura_init.h
@@ -18,7 +18,7 @@ class FontLoader;
 }
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace views {
@@ -28,11 +28,11 @@ class ViewsDelegate;
 // |resource_file| is the path to the apk file containing the resources.
 class VIEWS_MUS_EXPORT AuraInit {
  public:
-  AuraInit(mojo::Shell* shell, const std::string& resource_file);
+  AuraInit(mojo::Connector* connector, const std::string& resource_file);
   ~AuraInit();
 
  private:
-  void InitializeResources(mojo::Shell* shell);
+  void InitializeResources(mojo::Connector* connector);
 
 #if defined(OS_LINUX) && !defined(OS_ANDROID)
   skia::RefPtr<font_service::FontLoader> font_loader_;
diff --git a/ui/views/mus/native_widget_mus.cc b/ui/views/mus/native_widget_mus.cc
index d485155..2ecb52d 100644
--- a/ui/views/mus/native_widget_mus.cc
+++ b/ui/views/mus/native_widget_mus.cc
@@ -176,7 +176,7 @@ int ResizeBehaviorFromDelegate(WidgetDelegate* delegate) {
 // NativeWidgetMus, public:
 
 NativeWidgetMus::NativeWidgetMus(internal::NativeWidgetDelegate* delegate,
-                                 mojo::Shell* shell,
+                                 mojo::Connector* connector,
                                  mus::Window* window,
                                  mus::mojom::SurfaceType surface_type)
     : window_(window),
@@ -200,10 +200,10 @@ NativeWidgetMus::NativeWidgetMus(internal::NativeWidgetDelegate* delegate,
   // SoftwareOutputDeviceMus.
   if (!default_context_factory) {
     context_factory_.reset(
-        new SurfaceContextFactory(shell, window_, surface_type_));
+        new SurfaceContextFactory(connector, window_, surface_type_));
     aura::Env::GetInstance()->set_context_factory(context_factory_.get());
   }
-  window_tree_host_.reset(new WindowTreeHostMus(shell, this, window_));
+  window_tree_host_.reset(new WindowTreeHostMus(connector, this, window_));
   aura::Env::GetInstance()->set_context_factory(default_context_factory);
 }
 
diff --git a/ui/views/mus/native_widget_mus.h b/ui/views/mus/native_widget_mus.h
index 57cb55c..9e697a8 100644
--- a/ui/views/mus/native_widget_mus.h
+++ b/ui/views/mus/native_widget_mus.h
@@ -30,7 +30,7 @@ class Window;
 }
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -59,7 +59,7 @@ class VIEWS_MUS_EXPORT NativeWidgetMus : public internal::NativeWidgetPrivate,
                                          public aura::WindowTreeHostObserver {
  public:
   NativeWidgetMus(internal::NativeWidgetDelegate* delegate,
-                  mojo::Shell* shell,
+                  mojo::Connector* connector,
                   mus::Window* window,
                   mus::mojom::SurfaceType surface_type);
   ~NativeWidgetMus() override;
diff --git a/ui/views/mus/platform_test_helper_mus.cc b/ui/views/mus/platform_test_helper_mus.cc
index 918c550..ba6869c 100644
--- a/ui/views/mus/platform_test_helper_mus.cc
+++ b/ui/views/mus/platform_test_helper_mus.cc
@@ -7,6 +7,7 @@
 #include "base/command_line.h"
 #include "mojo/shell/background/background_shell.h"
 #include "mojo/shell/background/tests/test_application_catalog_store.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/cpp/shell_connection.h"
 #include "ui/views/mus/window_manager_connection.h"
@@ -52,9 +53,9 @@ class PlatformTestHelperMus : public PlatformTestHelper {
     shell_connection_->WaitForInitialize();
     // ui/views/mus requires a WindowManager running, for now use the desktop
     // one.
-    mojo::Shell* shell = shell_connection_.get();
-    shell->Connect("mojo:desktop_wm");
-    WindowManagerConnection::Create(shell_connection_.get());
+    mojo::Connector* connector = shell_connection_->connector();
+    connector->Connect("mojo:desktop_wm");
+    WindowManagerConnection::Create(connector);
   }
 
   ~PlatformTestHelperMus() override {
diff --git a/ui/views/mus/platform_window_mus.cc b/ui/views/mus/platform_window_mus.cc
index 07e3c6e..3961390 100644
--- a/ui/views/mus/platform_window_mus.cc
+++ b/ui/views/mus/platform_window_mus.cc
@@ -22,7 +22,7 @@ static uint32_t accelerated_widget_count = 1;
 }  // namespace
 
 PlatformWindowMus::PlatformWindowMus(ui::PlatformWindowDelegate* delegate,
-                                     mojo::Shell* shell,
+                                     mojo::Connector* connector,
                                      mus::Window* mus_window)
     : delegate_(delegate),
       mus_window_(mus_window),
@@ -48,7 +48,7 @@ PlatformWindowMus::PlatformWindowMus(ui::PlatformWindowDelegate* delegate,
       accelerated_widget, mus_window_->viewport_metrics().device_pixel_ratio);
 
   bitmap_uploader_.reset(new bitmap_uploader::BitmapUploader(mus_window_));
-  bitmap_uploader_->Init(shell);
+  bitmap_uploader_->Init(connector);
   prop_.reset(new ui::ViewProp(
       accelerated_widget, bitmap_uploader::kBitmapUploaderForAcceleratedWidget,
       bitmap_uploader_.get()));
diff --git a/ui/views/mus/platform_window_mus.h b/ui/views/mus/platform_window_mus.h
index 5cc440b..2d95a21 100644
--- a/ui/views/mus/platform_window_mus.h
+++ b/ui/views/mus/platform_window_mus.h
@@ -21,7 +21,7 @@ class BitmapUploader;
 }
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace ui {
@@ -36,7 +36,7 @@ class VIEWS_MUS_EXPORT PlatformWindowMus
       public NON_EXPORTED_BASE(mus::InputEventHandler) {
  public:
   PlatformWindowMus(ui::PlatformWindowDelegate* delegate,
-                    mojo::Shell* shell,
+                    mojo::Connector* connector,
                     mus::Window* mus_window);
   ~PlatformWindowMus() override;
 
diff --git a/ui/views/mus/screen_mus.cc b/ui/views/mus/screen_mus.cc
index 5b22354..7c763e7 100644
--- a/ui/views/mus/screen_mus.cc
+++ b/ui/views/mus/screen_mus.cc
@@ -7,7 +7,7 @@
 // #include "components/mus/public/interfaces/window_manager_constants.mojom.h"
 #include "mojo/converters/geometry/geometry_type_converters.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/gfx/display_finder.h"
 #include "ui/gfx/display_observer.h"
 #include "ui/views/mus/screen_mus_delegate.h"
@@ -75,10 +75,10 @@ ScreenMus::ScreenMus(ScreenMusDelegate* delegate)
 
 ScreenMus::~ScreenMus() {}
 
-void ScreenMus::Init(mojo::Shell* shell) {
+void ScreenMus::Init(mojo::Connector* connector) {
   gfx::Screen::SetScreenInstance(this);
 
-  shell->ConnectToInterface("mojo:mus", &display_manager_);
+  connector->ConnectToInterface("mojo:mus", &display_manager_);
 
   display_manager_->AddObserver(
       display_manager_observer_binding_.CreateInterfacePtrAndBind());
diff --git a/ui/views/mus/screen_mus.h b/ui/views/mus/screen_mus.h
index 0e9a352..04e4b5e 100644
--- a/ui/views/mus/screen_mus.h
+++ b/ui/views/mus/screen_mus.h
@@ -15,7 +15,7 @@
 #include "ui/views/mus/mus_export.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace views {
@@ -30,7 +30,7 @@ class VIEWS_MUS_EXPORT ScreenMus
   explicit ScreenMus(ScreenMusDelegate* delegate);
   ~ScreenMus() override;
 
-  void Init(mojo::Shell* shell);
+  void Init(mojo::Connector* connector);
 
  private:
   int FindDisplayIndexById(int64_t id) const;
diff --git a/ui/views/mus/surface_binding.cc b/ui/views/mus/surface_binding.cc
index c9e897a..e33e324 100644
--- a/ui/views/mus/surface_binding.cc
+++ b/ui/views/mus/surface_binding.cc
@@ -26,7 +26,7 @@
 #include "mojo/converters/geometry/geometry_type_converters.h"
 #include "mojo/converters/surfaces/surfaces_type_converters.h"
 #include "mojo/public/cpp/bindings/binding.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/views/mus/window_tree_host_mus.h"
 
 namespace views {
@@ -41,7 +41,7 @@ namespace views {
 class SurfaceBinding::PerConnectionState
     : public base::RefCounted<PerConnectionState> {
  public:
-  static PerConnectionState* Get(mojo::Shell* shell,
+  static PerConnectionState* Get(mojo::Connector* connector,
                                  mus::WindowTreeConnection* connection);
 
   scoped_ptr<cc::OutputSurface> CreateOutputSurface(
@@ -54,7 +54,8 @@ class SurfaceBinding::PerConnectionState
 
   friend class base::RefCounted<PerConnectionState>;
 
-  PerConnectionState(mojo::Shell* shell, mus::WindowTreeConnection* connection);
+  PerConnectionState(mojo::Connector* connector,
+                     mus::WindowTreeConnection* connection);
   ~PerConnectionState();
 
   void Init();
@@ -62,7 +63,7 @@ class SurfaceBinding::PerConnectionState
   static base::LazyInstance<
       base::ThreadLocalPointer<ConnectionToStateMap>>::Leaky window_states;
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   mus::WindowTreeConnection* connection_;
 
   // Set of state needed to create an OutputSurface.
@@ -78,7 +79,7 @@ base::LazyInstance<base::ThreadLocalPointer<
 
 // static
 SurfaceBinding::PerConnectionState* SurfaceBinding::PerConnectionState::Get(
-    mojo::Shell* shell,
+    mojo::Connector* connector,
     mus::WindowTreeConnection* connection) {
   ConnectionToStateMap* window_map = window_states.Pointer()->Get();
   if (!window_map) {
@@ -86,7 +87,7 @@ SurfaceBinding::PerConnectionState* SurfaceBinding::PerConnectionState::Get(
     window_states.Pointer()->Set(window_map);
   }
   if (!(*window_map)[connection]) {
-    (*window_map)[connection] = new PerConnectionState(shell, connection);
+    (*window_map)[connection] = new PerConnectionState(connector, connection);
     (*window_map)[connection]->Init();
   }
   return (*window_map)[connection];
@@ -108,9 +109,9 @@ SurfaceBinding::PerConnectionState::CreateOutputSurface(
 }
 
 SurfaceBinding::PerConnectionState::PerConnectionState(
-    mojo::Shell* shell,
+    mojo::Connector* connector,
     mus::WindowTreeConnection* connection)
-    : shell_(shell), connection_(connection) {}
+    : connector_(connector), connection_(connection) {}
 
 SurfaceBinding::PerConnectionState::~PerConnectionState() {
   ConnectionToStateMap* window_map = window_states.Pointer()->Get();
@@ -124,17 +125,17 @@ SurfaceBinding::PerConnectionState::~PerConnectionState() {
 }
 
 void SurfaceBinding::PerConnectionState::Init() {
-  shell_->ConnectToInterface("mojo:mus", &gpu_);
+  connector_->ConnectToInterface("mojo:mus", &gpu_);
 }
 
 // SurfaceBinding --------------------------------------------------------------
 
-SurfaceBinding::SurfaceBinding(mojo::Shell* shell,
+SurfaceBinding::SurfaceBinding(mojo::Connector* connector,
                                mus::Window* window,
                                mus::mojom::SurfaceType surface_type)
     : window_(window),
       surface_type_(surface_type),
-      state_(PerConnectionState::Get(shell, window->connection())) {}
+      state_(PerConnectionState::Get(connector, window->connection())) {}
 
 SurfaceBinding::~SurfaceBinding() {}
 
diff --git a/ui/views/mus/surface_binding.h b/ui/views/mus/surface_binding.h
index 0b468b5..2c6c5b6 100644
--- a/ui/views/mus/surface_binding.h
+++ b/ui/views/mus/surface_binding.h
@@ -16,7 +16,7 @@ class OutputSurface;
 }
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -32,7 +32,7 @@ namespace views {
 // connection.
 class VIEWS_MUS_EXPORT SurfaceBinding {
  public:
-  SurfaceBinding(mojo::Shell* shell,
+  SurfaceBinding(mojo::Connector* connector,
                  mus::Window* window,
                  mus::mojom::SurfaceType surface_type);
   ~SurfaceBinding();
diff --git a/ui/views/mus/surface_context_factory.cc b/ui/views/mus/surface_context_factory.cc
index 0d5bfee..840a16b 100644
--- a/ui/views/mus/surface_context_factory.cc
+++ b/ui/views/mus/surface_context_factory.cc
@@ -27,10 +27,10 @@ class FakeReflector : public ui::Reflector {
 }  // namespace
 
 SurfaceContextFactory::SurfaceContextFactory(
-    mojo::Shell* shell,
+    mojo::Connector* connector,
     mus::Window* window,
     mus::mojom::SurfaceType surface_type)
-    : surface_binding_(shell, window, surface_type),
+    : surface_binding_(connector, window, surface_type),
       next_surface_id_namespace_(1u) {}
 
 SurfaceContextFactory::~SurfaceContextFactory() {}
diff --git a/ui/views/mus/surface_context_factory.h b/ui/views/mus/surface_context_factory.h
index 72c85fd..6399d5a 100644
--- a/ui/views/mus/surface_context_factory.h
+++ b/ui/views/mus/surface_context_factory.h
@@ -16,7 +16,7 @@
 #include "ui/views/mus/surface_binding.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -27,7 +27,7 @@ namespace views {
 
 class VIEWS_MUS_EXPORT SurfaceContextFactory : public ui::ContextFactory {
  public:
-  SurfaceContextFactory(mojo::Shell* shell,
+  SurfaceContextFactory(mojo::Connector* connector,
                         mus::Window* window,
                         mus::mojom::SurfaceType surface_type);
   ~SurfaceContextFactory() override;
diff --git a/ui/views/mus/window_manager_connection.cc b/ui/views/mus/window_manager_connection.cc
index 10d373b..a7841fd 100644
--- a/ui/views/mus/window_manager_connection.cc
+++ b/ui/views/mus/window_manager_connection.cc
@@ -13,7 +13,7 @@
 #include "mojo/converters/geometry/geometry_type_converters.h"
 #include "mojo/converters/network/network_type_converters.h"
 #include "mojo/shell/public/cpp/connection.h"
-#include "mojo/shell/public/cpp/shell.h"
+#include "mojo/shell/public/cpp/connector.h"
 #include "ui/views/mus/native_widget_mus.h"
 #include "ui/views/mus/screen_mus.h"
 #include "ui/views/views_delegate.h"
@@ -31,9 +31,9 @@ base::LazyInstance<WindowManagerConnectionPtr>::Leaky lazy_tls_ptr =
 }  // namespace
 
 // static
-void WindowManagerConnection::Create(mojo::Shell* shell) {
+void WindowManagerConnection::Create(mojo::Connector* connector) {
   DCHECK(!lazy_tls_ptr.Pointer()->Get());
-  lazy_tls_ptr.Pointer()->Set(new WindowManagerConnection(shell));
+  lazy_tls_ptr.Pointer()->Set(new WindowManagerConnection(connector));
 }
 
 // static
@@ -60,17 +60,17 @@ NativeWidget* WindowManagerConnection::CreateNativeWidgetMus(
     internal::NativeWidgetDelegate* delegate) {
   std::map<std::string, std::vector<uint8_t>> properties = props;
   NativeWidgetMus::ConfigurePropertiesForNewWindow(init_params, &properties);
-  return new NativeWidgetMus(delegate, shell_, NewWindow(properties),
+  return new NativeWidgetMus(delegate, connector_, NewWindow(properties),
                              mus::mojom::SurfaceType::DEFAULT);
 }
 
-WindowManagerConnection::WindowManagerConnection(mojo::Shell* shell)
-    : shell_(shell), window_tree_connection_(nullptr) {
+WindowManagerConnection::WindowManagerConnection(mojo::Connector* connector)
+    : connector_(connector), window_tree_connection_(nullptr) {
   window_tree_connection_.reset(
-      mus::WindowTreeConnection::Create(this, shell_));
+      mus::WindowTreeConnection::Create(this, connector_));
 
   screen_.reset(new ScreenMus(this));
-  screen_->Init(shell);
+  screen_->Init(connector);
 
   ViewsDelegate::GetInstance()->set_native_widget_factory(base::Bind(
       &WindowManagerConnection::CreateNativeWidgetMus,
diff --git a/ui/views/mus/window_manager_connection.h b/ui/views/mus/window_manager_connection.h
index 0095728..896f9e7 100644
--- a/ui/views/mus/window_manager_connection.h
+++ b/ui/views/mus/window_manager_connection.h
@@ -15,7 +15,7 @@
 #include "ui/views/widget/widget.h"
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace views {
@@ -37,13 +37,13 @@ class VIEWS_MUS_EXPORT WindowManagerConnection
     : public NON_EXPORTED_BASE(mus::WindowTreeDelegate),
       public ScreenMusDelegate {
  public:
-  static void Create(mojo::Shell* shell);
+  static void Create(mojo::Connector* connector);
   static WindowManagerConnection* Get();
 
   // Destroys the singleton instance.
   static void Reset();
 
-  mojo::Shell* shell() { return shell_; }
+  mojo::Connector* connector() { return connector_; }
 
   mus::Window* NewWindow(const std::map<std::string,
                          std::vector<uint8_t>>& properties);
@@ -54,7 +54,7 @@ class VIEWS_MUS_EXPORT WindowManagerConnection
       internal::NativeWidgetDelegate* delegate);
 
  private:
-  explicit WindowManagerConnection(mojo::Shell* shell);
+  explicit WindowManagerConnection(mojo::Connector* connector);
   ~WindowManagerConnection() override;
 
   // mus::WindowTreeDelegate:
@@ -65,7 +65,7 @@ class VIEWS_MUS_EXPORT WindowManagerConnection
   void OnWindowManagerFrameValuesChanged() override;
 
 
-  mojo::Shell* shell_;
+  mojo::Connector* connector_;
   scoped_ptr<ScreenMus> screen_;
   scoped_ptr<mus::WindowTreeConnection> window_tree_connection_;
 
diff --git a/ui/views/mus/window_tree_host_mus.cc b/ui/views/mus/window_tree_host_mus.cc
index 6326e85..507adc5 100644
--- a/ui/views/mus/window_tree_host_mus.cc
+++ b/ui/views/mus/window_tree_host_mus.cc
@@ -16,13 +16,13 @@ namespace views {
 ////////////////////////////////////////////////////////////////////////////////
 // WindowTreeHostMus, public:
 
-WindowTreeHostMus::WindowTreeHostMus(mojo::Shell* shell,
+WindowTreeHostMus::WindowTreeHostMus(mojo::Connector* connector,
                                      NativeWidgetMus* native_widget,
                                      mus::Window* window)
     : native_widget_(native_widget),
       show_state_(ui::PLATFORM_WINDOW_STATE_UNKNOWN) {
   SetPlatformWindow(
-      make_scoped_ptr(new PlatformWindowMus(this, shell, window)));
+      make_scoped_ptr(new PlatformWindowMus(this, connector, window)));
   // The location of events is already transformed, and there is no way to
   // correctly determine the reverse transform. So, don't attempt to transform
   // event locations, else the root location is wrong.
diff --git a/ui/views/mus/window_tree_host_mus.h b/ui/views/mus/window_tree_host_mus.h
index a97475a..4044e8e 100644
--- a/ui/views/mus/window_tree_host_mus.h
+++ b/ui/views/mus/window_tree_host_mus.h
@@ -12,7 +12,7 @@
 class SkBitmap;
 
 namespace mojo {
-class Shell;
+class Connector;
 }
 
 namespace mus {
@@ -27,7 +27,7 @@ class PlatformWindowMus;
 
 class VIEWS_MUS_EXPORT WindowTreeHostMus : public aura::WindowTreeHostPlatform {
  public:
-  WindowTreeHostMus(mojo::Shell* shell,
+  WindowTreeHostMus(mojo::Connector* connector,
                     NativeWidgetMus* native_widget_,
                     mus::Window* window);
   ~WindowTreeHostMus() override;