Panels not getting focus on Linux when expanded from API on Linux.

chrome/browser/ui/panels/panel_browser_window_gtk.h

Index: chrome/browser/ui/panels/panel_browser_window_gtk.h
diff --git a/chrome/browser/ui/panels/panel_browser_window_gtk.h b/chrome/browser/ui/panels/panel_browser_window_gtk.h
index 04850aed695a521a9375dd6a1805bcd76a168487..936dcef4b5dd701ab0fca06aed4b29a2e16d5659 100644
--- a/chrome/browser/ui/panels/panel_browser_window_gtk.h
+++ b/chrome/browser/ui/panels/panel_browser_window_gtk.h
@@ -41,6 +41,11 @@ class PanelBrowserWindowGtk : public BrowserWindowGtk,
   // ui::WorkAreaWatcherXObserver override
   virtual void WorkAreaChanged() OVERRIDE;
 
+  // Overrides BrowserWindowGtk::NotificationObserver::Observe
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
  protected:
   // BrowserWindowGtk overrides
   virtual bool GetWindowEdge(int x, int y, GdkWindowEdge* edge) OVERRIDE;
@@ -196,6 +201,8 @@ class PanelBrowserWindowGtk : public BrowserWindowGtk,
   // from where the last one left.
   gfx::Rect last_animation_progressed_bounds_;
 
+  content::NotificationRegistrar registrar_;
+
   DISALLOW_COPY_AND_ASSIGN(PanelBrowserWindowGtk);
 };