Make platform apps use and require a different container ("shell" instead of "panel")

chrome/browser/ui/browser.h

Index: chrome/browser/ui/browser.h
diff --git a/chrome/browser/ui/browser.h b/chrome/browser/ui/browser.h
index 37456d382643aeeb5236f96c33d3d08be8511f03..db0a17d9f89944dc30bd499f16e4a83942971857 100644
--- a/chrome/browser/ui/browser.h
+++ b/chrome/browser/ui/browser.h
@@ -97,6 +97,7 @@ class Browser : public TabHandlerDelegate,
     TYPE_TABBED = 1,
     TYPE_POPUP = 2,
     TYPE_PANEL = 3,
+    TYPE_SHELL = 4
   };
 
   // Possible elements of the Browser window.
@@ -854,6 +855,7 @@ class Browser : public TabHandlerDelegate,
   bool is_type_tabbed() const { return type_ == TYPE_TABBED; }
   bool is_type_popup() const { return type_ == TYPE_POPUP; }
   bool is_type_panel() const { return type_ == TYPE_PANEL; }
+  bool is_type_shell() const { return type_ == TYPE_SHELL; }
 
   bool is_app() const;
   bool is_devtools() const;