aura: Fix WidgetFocusChangeListener::OnNativeFocusChange().

In Aura, we were passing the newly-focused view through
views::WidgetFocusManager::OnWidgetFocusEvent()'s
"focused_before" parameter.  This made us not close
extension popups when they lost the focus.

(Note that a popup still doesn't get closed upon clicking
outside of the popup on the desktop, presumably because the
popup retains the focus in Ash.)

BUG=132697
TEST=added, also manual testing


Review URL: https://chromiumcodereview.appspot.com/10562025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@142858 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ui/aura/demo/demo_main.cc b/ui/aura/demo/demo_main.cc
index 530dc520..da57329a 100644
--- a/ui/aura/demo/demo_main.cc
+++ b/ui/aura/demo/demo_main.cc
@@ -39,7 +39,7 @@
   }
   virtual void OnBoundsChanged(const gfx::Rect& old_bounds,
                                const gfx::Rect& new_bounds) OVERRIDE {}
-  virtual void OnFocus() OVERRIDE {}
+  virtual void OnFocus(aura::Window* old_focused_window) OVERRIDE {}
   virtual void OnBlur() OVERRIDE {}
   virtual bool OnKeyEvent(aura::KeyEvent* event) OVERRIDE {
     return false;