The app launcher had a height of zero as it was not getting preferred size up...

chrome/browser/tab_contents/tab_contents_delegate.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_
 #define CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 268 matching lines @@
   // Returns the native window framing the view containing the tab contents.
   virtual gfx::NativeWindow GetFrameNativeWindow() { return NULL; }
 
   // Notifies the delegate about the creation of a new TabContents. This
   // typically happens when popups are created.
   virtual void TabContentsCreated(TabContents* new_contents) {}
 
   // Returns whether infobars are enabled. Overrideable by child classes.
   virtual bool infobars_enabled() { return true; }
 
+  // Whether the renderer should report its preferred size when it changes by
+  // calling UpdatePreferredSize().
+  // Note that this is set when the RenderViewHost is created and cannot be
+  // changed after that.
+  virtual bool ShouldEnablePreferredSizeNotifications() { return false; }
+
   // Notification that the preferred size of the contents has changed.
-  // Only called if RenderViewHost::EnablePreferredSizeChangedMode() was called.
+  // Only called if ShouldEnablePreferredSizeNotifications() returns true.
   virtual void UpdatePreferredSize(const gfx::Size& pref_size) {}
 
  protected:
   ~TabContentsDelegate() {}
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_