Keep a web dialog window centered over the content area

ui/aura/window.h

Index: ui/aura/window.h
diff --git a/ui/aura/window.h b/ui/aura/window.h
index 09039d32bd196f51a9ebc1a7bd3869e66a240835..92e5f480c0a24410fe4d8c9ddf79d0dace913733 100644
--- a/ui/aura/window.h
+++ b/ui/aura/window.h
@@ -359,6 +359,12 @@ class AURA_EXPORT Window : public ui::LayerDelegate,
   void PrintWindowHierarchy(int depth) const;
 #endif
 
+  // Returns true if the window is a constrained window.
+  void set_is_constrained_window(bool is_constrained_window) {

[sky, 2012/09/14 22:50:44]

Window shouldn't contain chrome specific properties like this. By property I
meant something via SetProperty.

+    is_constrained_window_ = is_constrained_window;
+  }
+  bool is_constrained_window() const { return is_constrained_window_; }
+
  private:
   friend class LayoutManager;
 
@@ -500,6 +506,9 @@ class AURA_EXPORT Window : public ui::LayerDelegate,
 
   std::map<const void*, Value> prop_map_;
 
+  // True if this is a constrained window.
+  bool is_constrained_window_;
+
   DISALLOW_COPY_AND_ASSIGN(Window);
 };