First shot at implementing drag&drop for Aura

ui/aura/window.h

Index: ui/aura/window.h
diff --git a/ui/aura/window.h b/ui/aura/window.h
index 485bcb41b5ea3b6a7df52550b665eb843546f619..ad6c1ff20c04ac70816b2376c5cb5263198ec83a 100644
--- a/ui/aura/window.h
+++ b/ui/aura/window.h
@@ -42,6 +42,7 @@ class MouseEvent;
 class ToplevelWindowContainer;
 class TouchEvent;
 class WindowDelegate;
+class WindowDragDropDelegate;
 class WindowObserver;
 
 namespace internal {
@@ -90,6 +91,11 @@ class AURA_EXPORT Window : public ui::LayerDelegate {
   void set_user_data(void* user_data) { user_data_ = user_data; }
   void* user_data() const { return user_data_; }
 
+  WindowDragDropDelegate* drag_drop_delegate() { return drag_drop_delegate_; }
+  void set_drag_drop_delegate(WindowDragDropDelegate* drag_drop_delegate) {
+    drag_drop_delegate_ = drag_drop_delegate;
+  }
+
   // Changes the visibility of the window.
   void Show();
   void Hide();
@@ -349,6 +355,9 @@ class AURA_EXPORT Window : public ui::LayerDelegate {
   // implementation.
   std::map<const char*, void*> prop_map_;
 
+  // Delegate for handling drag and drop operations.
+  WindowDragDropDelegate* drag_drop_delegate_;

[Ben Goodger (Google), 2011/11/11 17:26:53]

I think we should not add this directly to Window. Instead, this can be a
property that gets set. See client/aura_constants.h

[varunjain, 2011/11/15 19:39:33]

Done.

+
   DISALLOW_COPY_AND_ASSIGN(Window);
 };