Make panel adjust bounds per preferred size change notification on Windows.

content/browser/renderer_host/render_view_host_delegate.h

Index: content/browser/renderer_host/render_view_host_delegate.h
===================================================================
--- content/browser/renderer_host/render_view_host_delegate.h	(revision 98900)
+++ content/browser/renderer_host/render_view_host_delegate.h	(working copy)
@@ -150,9 +150,6 @@
     // retrieved by doing a Shift-Tab.
     virtual void TakeFocus(bool reverse) = 0;
 
-    // The contents' preferred size changed.
-    virtual void UpdatePreferredSize(const gfx::Size& pref_size) = 0;
-
    protected:
     virtual ~View() {}
   };
@@ -375,6 +372,9 @@
   // Notification that the page wants to go into or out of fullscreen mode.
   virtual void ToggleFullscreenMode(bool enter_fullscreen) {}
 
+  // The contents' preferred size changed.
+  virtual void UpdatePreferredSize(const gfx::Size& pref_size) {}
+
  protected:
   virtual ~RenderViewHostDelegate() {}
 };