chromeos: Refactor shelf to create ShelfView earlier in startup

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 2d36d457672a27fa6712ce10fb719013481a9b5a..5b0f96abd4b272f7a11f42453c6de40d359e4da8 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -419,21 +419,6 @@ FirstRunHelper* Shell::CreateFirstRunHelper() {
   return new FirstRunHelperImpl;
 }
 
-void Shell::CreateShelfView() {
-  // Must occur after SessionController creation and user login.
-  DCHECK(session_controller());
-  DCHECK_GT(session_controller()->NumberOfLoggedInUsers(), 0);
-
-  // Notify the ShellDelegate that the shelf is being initialized.
-  // TODO(msw): Refine ChromeLauncherController lifetime management.
-  shell_delegate_->ShelfInit();
-
-  if (!shelf_window_watcher_)
-    shelf_window_watcher_ = base::MakeUnique<ShelfWindowWatcher>(shelf_model());
-  for (WmWindow* root_window : shell_port_->GetAllRootWindows())
-    root_window->GetRootWindowController()->CreateShelfView();
-}
-
 void Shell::SetLargeCursorSizeInDip(int large_cursor_size_in_dip) {
   window_tree_host_manager_->cursor_window_controller()
       ->SetLargeCursorSizeInDip(large_cursor_size_in_dip);
@@ -1233,11 +1218,10 @@ void Shell::OnWindowActivated(
 }
 
 void Shell::OnSessionStateChanged(session_manager::SessionState state) {
-  // Create the shelf when a session becomes active. It's safe to do this
+  // Initialize the shelf when a session becomes active. It's safe to do this
   // multiple times (e.g. initial login vs. multiprofile add session).
   if (state == session_manager::SessionState::ACTIVE) {
-    CreateShelfView();
-
+    InitializeShelf();
     if (GetAshConfig() != Config::MASH) {
       // Recreate the keyboard after initial login and after multiprofile login.
       CreateKeyboard();
@@ -1261,6 +1245,22 @@ void Shell::OnLockStateChanged(bool locked) {
 #endif
 }
 
+void Shell::InitializeShelf() {
+  // Must occur after SessionController creation and user login.
+  DCHECK(session_controller());
+  DCHECK_GT(session_controller()->NumberOfLoggedInUsers(), 0);
+
+  // Notify the ShellDelegate that the shelf is being initialized.
+  // TODO(msw): Refine ChromeLauncherController lifetime management.
+  shell_delegate_->ShelfInit();
+
+  if (!shelf_window_watcher_)
+    shelf_window_watcher_ = base::MakeUnique<ShelfWindowWatcher>(shelf_model());
+
+  for (RootWindowController* root : GetAllRootWindowControllers())
+    root->InitializeShelf();
+}
+
 void Shell::OnPrefServiceInitialized(
     std::unique_ptr<::PrefService> pref_service) {
   if (!instance_)