Proper MouseEvent targeting. Adds a Window method that locates a Window for a given point.

aura/window.h

Index: aura/window.h
===================================================================
--- aura/window.h	(revision 98650)
+++ aura/window.h	(working copy)
@@ -27,6 +27,7 @@
 
 // Aura window implementation. Interesting events are sent to the
 // WindowDelegate.
+// TODO(beng): resolve ownership.
 class Window {
  public:
   enum Visibility {
@@ -80,9 +81,26 @@
   void AddChild(Window* child);
   void RemoveChild(Window* child);
 
+  static void ConvertPointToWindow(Window* source,
+                                   Window* target,
+                                   gfx::Point* point);
+
   // Handles a mouse event. Returns true if handled.
   bool OnMouseEvent(const MouseEvent& event);
 
+  WindowDelegate* delegate() { return delegate_; }
+
+  // Returns true if the mouse pointer at the specified |point| can trigger an
+  // event for this Window.
+  // TODO(beng):
+  // A Window can supply a hit-test mask to cause some portions of itself to not
+  // trigger events, causing the events to fall through to the Window behind.
+  bool HitTest(const gfx::Point& point);
+
+  // Returns the Window that most closely encloses |point| for the purposes of
+  // event targeting.
+  Window* GetEventHandlerForPoint(const gfx::Point& point);
+
  private:
   typedef std::vector<Window*> Windows;