Change panels to be able to turn off autoresize.

chrome/browser/ui/browser_window.h

Index: chrome/browser/ui/browser_window.h
diff --git a/chrome/browser/ui/browser_window.h b/chrome/browser/ui/browser_window.h
index c7f03d468e1f1837d33aeb74902ef048aeb39268..f3597062d1091bd32bd48343e0db6e8cc2cb444c 100644
--- a/chrome/browser/ui/browser_window.h
+++ b/chrome/browser/ui/browser_window.h
@@ -333,6 +333,10 @@ class BrowserWindow : public BaseWindow {
   virtual void UpdatePreferredSize(content::WebContents* web_contents,
                                    const gfx::Size& pref_size) {}
 
+  // Invoked when the contents auto-resized and the container should match it.
+  virtual void ResizeDueToAutoResize(content::WebContents* web_contents,
+                                     const gfx::Size& new_size) {}
+
   // Construct a BrowserWindow implementation for the specified |browser|.
   static BrowserWindow* CreateBrowserWindow(Browser* browser);