Refactors DimWindow and moves to ash/common

ash/common/wm_window.cc

Index: ash/common/wm_window.cc
diff --git a/ash/mus/bridge/wm_shelf_mus.cc b/ash/common/wm_window.cc
similarity index 26%
copy from ash/mus/bridge/wm_shelf_mus.cc
copy to ash/common/wm_window.cc
index c8ee95c08ae060a4f10dd66140438d251d8a41e0..fe7f61606a5b3096dcc91e6121a9e27c119d9614 100644
--- a/ash/mus/bridge/wm_shelf_mus.cc
+++ b/ash/common/wm_window.cc
@@ -2,35 +2,36 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ash/mus/bridge/wm_shelf_mus.h"
-
-#include "ash/common/shelf/shelf_widget.h"
-#include "ash/common/wm_root_window_controller.h"
-#include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 
+#include "base/memory/ptr_util.h"
+#include "base/supports_user_data.h"
+
 namespace ash {
-namespace mus {
-
-WmShelfMus::WmShelfMus(WmWindow* root_window) {
-  DCHECK(root_window);
-  WmShell::Get()->CreateShelfDelegate();
-  CreateShelfWidget(root_window);
-  InitializeShelf();
-  WmShell::Get()->NotifyShelfCreatedForRootWindow(root_window);
-  shelf_widget()->PostCreateShelf();
+
+class WmWindow::SupportsUserDataImpl : public base::SupportsUserData {

[James Cook, 2016/09/09 00:03:35]

Is the whole point of this to get around the protected virtual destructor of
base::SupportsUserData? WDYT of making that destructor public so you can just
allocate one?

[sky, 2016/09/09 03:50:04]

I think it's better to keep SUDs destructor protected so that it's up to the
implementation to decide lifetime control. For example, some subclasses may not
want a public destructor either.

+ public:
+  SupportsUserDataImpl() {}
+  ~SupportsUserDataImpl() override {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SupportsUserDataImpl);
+};
+
+base::SupportsUserData* WmWindow::GetUserData() {
+  return user_data_.get();
 }
 
-WmShelfMus::~WmShelfMus() {
-  ShutdownShelfWidget();
-  DestroyShelfWidget();
-  ShutdownShelf();
+WmWindow::WmWindow() : user_data_(base::MakeUnique<SupportsUserDataImpl>()) {}
+
+WmWindow::~WmWindow() {
+  // Subclasses should explicitly destroy |user_data_| in destructor to ensure
+  // pure virtual methods are still valid while destroying |user_data_|.

[James Cook, 2016/09/09 00:03:35]

Thanks for documenting this.

+  DCHECK(!user_data_);
 }
 
-void WmShelfMus::WillDeleteShelfLayoutManager() {
-  ShutdownShelfWidget();
-  WmShelf::WillDeleteShelfLayoutManager();
+void WmWindow::DestroyUserData() {
+  user_data_.reset();
 }
 
-}  // namespace mus
 }  // namespace ash