Cursor state should be global among all root windows for desktop Aura

ui/views/widget/desktop_aura/desktop_native_cursor_manager.h

Index: ui/views/widget/desktop_aura/desktop_native_cursor_manager.h
diff --git a/ui/views/widget/desktop_aura/desktop_native_cursor_manager.h b/ui/views/widget/desktop_aura/desktop_native_cursor_manager.h
index 563131d92cc006e23e5332a3bc6c42b8e241155f..81103133b27035d192c8cb5407608ea2fd51060a 100644
--- a/ui/views/widget/desktop_aura/desktop_native_cursor_manager.h
+++ b/ui/views/widget/desktop_aura/desktop_native_cursor_manager.h
@@ -5,8 +5,11 @@
 #ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_CURSOR_MANAGER_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_NATIVE_CURSOR_MANAGER_H_
 
+#include <set>
+
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
+#include "ui/aura/window_observer.h"
 #include "ui/views/corewm/native_cursor_manager.h"
 #include "ui/views/views_export.h"
 
@@ -25,10 +28,12 @@ namespace corewm {
 class NativeCursorManagerDelegate;
 }
 
-// A NativeCursorManager that interacts with only one RootWindow. (Unlike the
-// one in ash, which interacts with all the RootWindows that ash knows about.)
+// A NativeCursorManager that performs the desktop-specific setting of cursor
+// state. Similar to AshNativeCursorManager, it also communicates these changes
+// to all root windows.
 class VIEWS_EXPORT DesktopNativeCursorManager
-    : public views::corewm::NativeCursorManager {
+    : public views::corewm::NativeCursorManager,
+      public aura::WindowObserver {
  public:
   DesktopNativeCursorManager(
       aura::RootWindow* window,
@@ -38,7 +43,13 @@ class VIEWS_EXPORT DesktopNativeCursorManager
   // Builds a cursor and sets the internal platform representation.
   gfx::NativeCursor GetInitializedCursor(int type);
 
+  // Overridden from aura::WindowObserver:
+  virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
+
  private:
+  // Invoked from destructor and OnWindowDestroyed() to cleanup.
+  void Shutdown();
+
   // Overridden from views::corewm::NativeCursorManager:
   virtual void SetDisplay(
       const gfx::Display& display,
@@ -59,10 +70,16 @@ class VIEWS_EXPORT DesktopNativeCursorManager
       bool enabled,
       views::corewm::NativeCursorManagerDelegate* delegate) OVERRIDE;
 
+  // The root window for which this DesktopNativeCursorManager was created.
   aura::RootWindow* root_window_;
+
   scoped_ptr<DesktopCursorLoaderUpdater> cursor_loader_updater_;
   scoped_ptr<ui::CursorLoader> cursor_loader_;
 
+  // The set of all root windows to notify of changes in cursor state.
+  typedef std::set<aura::RootWindow*> RootWindows;
+  static RootWindows* root_windows_;
+
   DISALLOW_COPY_AND_ASSIGN(DesktopNativeCursorManager);
 };