mash: Move ownership of ShelfDelegate to WmShell

ash/common/wm_shell.cc

Index: ash/common/wm_shell.cc
diff --git a/ash/common/wm_shell.cc b/ash/common/wm_shell.cc
index f0ed84ed71194a1548ca50c8f78008d0f1fda893..034f4820266aeb75b20c41330abdbabbface37ae 100644
--- a/ash/common/wm_shell.cc
+++ b/ash/common/wm_shell.cc
@@ -11,6 +11,7 @@
 #include "ash/common/focus_cycler.h"
 #include "ash/common/keyboard/keyboard_ui.h"
 #include "ash/common/shelf/app_list_shelf_item_delegate.h"
+#include "ash/common/shelf/shelf_delegate.h"
 #include "ash/common/shelf/shelf_model.h"
 #include "ash/common/shell_delegate.h"
 #include "ash/common/shell_window_ids.h"
@@ -67,6 +68,8 @@ void WmShell::Shutdown() {
   // ShelfItemDelegate subclasses it owns have complex cleanup to run (e.g. ARC
   // shelf items in Chrome) so explicitly shutdown early.
   shelf_model_->DestroyItemDelegates();
+  // Must be destroyed before FocusClient.
+  shelf_delegate_.reset();
 }
 
 void WmShell::OnMaximizeModeStarted() {
@@ -108,6 +111,11 @@ void WmShell::RemoveLockStateObserver(LockStateObserver* observer) {
   lock_state_observers_.RemoveObserver(observer);
 }
 
+void WmShell::SetShelfDelegateForTesting(
+    std::unique_ptr<ShelfDelegate> test_delegate) {
+  shelf_delegate_ = std::move(test_delegate);
+}
+
 WmShell::WmShell(std::unique_ptr<ShellDelegate> shell_delegate)
     : delegate_(std::move(shell_delegate)),
       focus_cycler_(new FocusCycler),
@@ -195,6 +203,13 @@ void WmShell::DeleteSystemTrayDelegate() {
   system_tray_delegate_.reset();
 }
 
+void WmShell::CreateShelfDelegate() {

[msw, 2016/07/23 00:02:36]

Could we just do this once in the ctor?

[James Cook, 2016/07/23 00:38:03]

No. It must be done after login. Moved the DCHECKS from ash::Shell to here to
make that more clear.

+  // May be called multiple times as shelves are created and destroyed.
+  if (shelf_delegate_)
+    return;
+  shelf_delegate_.reset(delegate_->CreateShelfDelegate(shelf_model_.get()));
+}
+
 void WmShell::DeleteWindowCycleController() {
   window_cycle_controller_.reset();
 }