chrome/chromeos: Fix launching chrome as a mus client.

Avoid initializaing ash::Shell when running chrome as a mus client. This
requires a number of components to be turned off that depend on a Shell
instance.

Notable changes:
. Do not initialize ash::Shell when chrome is launched as a mus client.
  This is because the window-management and system-ui functionality are
  provided by separate mus clients (desktop_wm and ash_sysui).

. Turn off AccessibilityManager (and MagnificationManager) when launching
  chrome as a mus client. Accessibility should be a separate service.
  That work is tracked in crbug.com/557401

. Turn off PowerButtonObserver, DataPromoNotification, and EventRewriter.
  These too should be separate mus/mojo apps.

BUG=585918

Review URL: https://codereview.chromium.org/1706593002

Cr-Commit-Position: refs/heads/master@{#375808}

4 files changed, 54 insertions, 24 deletions

diff --git a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
index 5300d0a..1cb9f9a 100644
--- a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
+++ b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
@@ -188,6 +188,13 @@ void InitializeNetworkPortalDetector() {
   }
 }
 
+bool IsRunningAsMusClient() {
+#if defined(MOJO_SHELL_CLIENT)
+  return !!content::MojoShellConnection::Get();
+#endif
+  return false;
+}
+
 }  // namespace
 
 namespace internal {
@@ -378,7 +385,7 @@ void ChromeBrowserMainPartsChromeos::PostMainMessageLoopStart() {
 // about_flags settings are applied in ChromeBrowserMainParts::PreCreateThreads.
 void ChromeBrowserMainPartsChromeos::PreMainMessageLoopRun() {
 #if defined(MOJO_SHELL_CLIENT)
-  if (content::MojoShellConnection::Get()) {
+  if (IsRunningAsMusClient()) {
     interface_factory_.reset(new ChromeInterfaceFactory);
     content::MojoShellConnection::Get()->AddListener(interface_factory_.get());
   }
@@ -473,10 +480,16 @@ void ChromeBrowserMainPartsChromeos::PreProfileInit() {
 
   media::SoundsManager::Create();
 
-  // Initialize magnification manager before ash tray is created. And this must
-  // be placed after UserManager::SessionStarted();
-  AccessibilityManager::Initialize();
-  MagnificationManager::Initialize();
+  if (!IsRunningAsMusClient()) {
+    // Initialize magnification manager before ash tray is created. And this
+    // must be placed after UserManager::SessionStarted();
+    // TODO(sad): These components expects the ash::Shell instance to be
+    // created. However, when running as a mus-client, an ash::Shell instance is
+    // not created. These accessibility services should instead be exposed as
+    // separate services. crbug.com/557401
+    AccessibilityManager::Initialize();
+    MagnificationManager::Initialize();
+  }
 
   wallpaper::WallpaperManagerBase::SetPathIds(
       chrome::DIR_USER_DATA,
@@ -707,21 +720,25 @@ void ChromeBrowserMainPartsChromeos::PreBrowserStart() {
 void ChromeBrowserMainPartsChromeos::PostBrowserStart() {
   system::InputDeviceSettings::Get()->InitTouchDevicesStatusFromLocalPrefs();
 
-  // These are dependent on the ash::Shell singleton already having been
-  // initialized.
-  // TODO(oshima): Remove ash dependency in PowerButtonObserver.
-  // crbug.com/408832.
-  power_button_observer_.reset(new PowerButtonObserver);
-  data_promo_notification_.reset(new DataPromoNotification());
-
-  keyboard_event_rewriters_.reset(new EventRewriterController());
-  keyboard_event_rewriters_->AddEventRewriter(
-      scoped_ptr<ui::EventRewriter>(new KeyboardDrivenEventRewriter()));
-  keyboard_event_rewriters_->AddEventRewriter(
-      scoped_ptr<ui::EventRewriter>(new SpokenFeedbackEventRewriter()));
-  keyboard_event_rewriters_->AddEventRewriter(scoped_ptr<ui::EventRewriter>(
-      new EventRewriter(ash::Shell::GetInstance()->sticky_keys_controller())));
-  keyboard_event_rewriters_->Init();
+  if (!IsRunningAsMusClient()) {
+    // These are dependent on the ash::Shell singleton already having been
+    // initialized. Consequently, these cannot be used when running as a mus
+    // client.
+    // TODO(oshima): Remove ash dependency in PowerButtonObserver.
+    // crbug.com/408832.
+    power_button_observer_.reset(new PowerButtonObserver);
+    data_promo_notification_.reset(new DataPromoNotification());
+
+    keyboard_event_rewriters_.reset(new EventRewriterController());
+    keyboard_event_rewriters_->AddEventRewriter(
+        scoped_ptr<ui::EventRewriter>(new KeyboardDrivenEventRewriter()));
+    keyboard_event_rewriters_->AddEventRewriter(
+        scoped_ptr<ui::EventRewriter>(new SpokenFeedbackEventRewriter()));
+    keyboard_event_rewriters_->AddEventRewriter(
+        scoped_ptr<ui::EventRewriter>(new EventRewriter(
+            ash::Shell::GetInstance()->sticky_keys_controller())));
+    keyboard_event_rewriters_->Init();
+  }
 
   ChromeBrowserMainPartsLinux::PostBrowserStart();
 }
diff --git a/chrome/browser/notifications/login_state_notification_blocker_chromeos.cc b/chrome/browser/notifications/login_state_notification_blocker_chromeos.cc
index 79b3617..d7f5b96 100644
--- a/chrome/browser/notifications/login_state_notification_blocker_chromeos.cc
+++ b/chrome/browser/notifications/login_state_notification_blocker_chromeos.cc
@@ -20,8 +20,11 @@ LoginStateNotificationBlockerChromeOS::LoginStateNotificationBlockerChromeOS(
       locked_(false),
       observing_(true) {
   // This class is created in the ctor of NotificationUIManager which is created
-  // when a notification is created, so ash::Shell should be initialized.
-  ash::Shell::GetInstance()->AddShellObserver(this);
+  // when a notification is created, so ash::Shell should be initialized, except
+  // when running as a mus client (ash::Shell is not initialized when that is
+  // the case).
+  if (ash::Shell::HasInstance())
+    ash::Shell::GetInstance()->AddShellObserver(this);
 
   // LoginState may not exist in some tests.
   if (chromeos::LoginState::IsInitialized())
@@ -65,7 +68,8 @@ void LoginStateNotificationBlockerChromeOS::OnLockStateChanged(bool locked) {
 }
 
 void LoginStateNotificationBlockerChromeOS::OnAppTerminating() {
-  ash::Shell::GetInstance()->RemoveShellObserver(this);
+  if (ash::Shell::HasInstance())
+    ash::Shell::GetInstance()->RemoveShellObserver(this);
   chromeos::UserAddingScreen::Get()->RemoveObserver(this);
   observing_ = false;
 }
diff --git a/chrome/browser/ui/ash/ash_util.cc b/chrome/browser/ui/ash/ash_util.cc
index 23622fe..3571624 100644
--- a/chrome/browser/ui/ash/ash_util.cc
+++ b/chrome/browser/ui/ash/ash_util.cc
@@ -11,10 +11,16 @@
 #include "chrome/browser/ui/host_desktop.h"
 #include "ui/aura/window_event_dispatcher.h"
 
+#if defined(MOJO_SHELL_CLIENT)
+#include "content/public/common/mojo_shell_connection.h"
+#endif
+
 namespace chrome {
 
 bool ShouldOpenAshOnStartup() {
-#if defined(OS_CHROMEOS)
+#if defined(OS_CHROMEOS) && defined(MOJO_SHELL_CLIENT)
+  return !content::MojoShellConnection::Get();
+#elif defined(OS_CHROMEOS)
   return true;
 #else
   return false;
diff --git a/chrome/browser/ui/window_sizer/window_sizer_ash.cc b/chrome/browser/ui/window_sizer/window_sizer_ash.cc
index 918b957..1112648 100644
--- a/chrome/browser/ui/window_sizer/window_sizer_ash.cc
+++ b/chrome/browser/ui/window_sizer/window_sizer_ash.cc
@@ -7,6 +7,7 @@
 #include "ash/shell.h"
 #include "ash/wm/window_positioner.h"
 #include "ash/wm/window_state.h"
+#include "chrome/browser/ui/ash/ash_util.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "ui/aura/window.h"
@@ -15,6 +16,8 @@
 
 bool WindowSizer::GetBrowserBoundsAsh(gfx::Rect* bounds,
                                       ui::WindowShowState* show_state) const {
+  if (!chrome::ShouldOpenAshOnStartup())
+    return false;
   if (!browser_ ||
       browser_->host_desktop_type() != chrome::HOST_DESKTOP_TYPE_ASH)
     return false;