Fix Panel to always detect when a tab is added.

chrome/browser/ui/panels/panel.h

Index: chrome/browser/ui/panels/panel.h
diff --git a/chrome/browser/ui/panels/panel.h b/chrome/browser/ui/panels/panel.h
index 53d424c7266bdc5bfaf2feeda00b76c090cd34aa..64ff50c78eefb25575e497014a1db6e8acb42930 100644
--- a/chrome/browser/ui/panels/panel.h
+++ b/chrome/browser/ui/panels/panel.h
@@ -10,6 +10,7 @@
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "chrome/browser/tabs/tab_strip_model_observer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "ui/gfx/rect.h"
@@ -28,7 +29,9 @@ class RenderViewHost;
 //   Panel size is restricted to certain limits.
 // - Invoke an appropriate PanelManager function to do stuff that might affect
 //   other Panels.  For example deleting a panel would rearrange other panels.
-class Panel : public BrowserWindow, public content::NotificationObserver {
+class Panel : public BrowserWindow,
+              public TabStripModelObserver,
+              public content::NotificationObserver {
  public:
   enum ExpansionState {
    // The panel is fully expanded with both title-bar and the client-area.
@@ -169,6 +172,11 @@ class Panel : public BrowserWindow, public content::NotificationObserver {
                                 const gfx::Rect& rect) OVERRIDE;
   virtual void ShowAvatarBubbleFromAvatarButton() OVERRIDE;
 
+  // TabStripModelObserver overrides.
+  virtual void TabInsertedAt(TabContentsWrapper* contents,
+                             int index,
+                             bool foreground) OVERRIDE;
+
   // content::NotificationObserver overrides.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
@@ -188,6 +196,9 @@ class Panel : public BrowserWindow, public content::NotificationObserver {
   // until the window has been created. (e.g. GTK)
   void OnWindowSizeAvailable();
 
+  // Asynchronous completion of panel close request.
+  void OnNativePanelClosed();
+
   NativePanel* native_panel() { return native_panel_; }
   Browser* browser() const;
   ExpansionState expansion_state() const { return expansion_state_; }
@@ -217,6 +228,8 @@ class Panel : public BrowserWindow, public content::NotificationObserver {
   // NULL might be returned if the tab has not been added.
   RenderViewHost* GetRenderViewHost() const;
 
+  void EnableAutoResize(RenderViewHost* render_view_host);
+
   // Requests RenderViewHost not to show the scrollbars till |max_size_| since
   // the panel can grow to |max_size_|.
   void RequestRenderViewHostToDisableScrollbars(