Don't use browser windows for platform app shell windows

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 8c0e8b8bebe23757bb86b29c2761665167e0994f..4ae114bbbc5d9d42ad34e7f3ab1f05822e8ee08f 100644
--- a/chrome/browser/ui/browser.h
+++ b/chrome/browser/ui/browser.h
@@ -98,8 +98,7 @@ class Browser : public TabHandlerDelegate,
     // BrowserTest.StartMaximized.
     TYPE_TABBED = 1,
     TYPE_POPUP = 2,
-    TYPE_PANEL = 3,
-    TYPE_SHELL = 4
+    TYPE_PANEL = 3
   };
 
   // Possible elements of the Browser window.
@@ -859,7 +858,6 @@ 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;