Revert 132856 - Aura/ash split: Remove hacks and get chrome linking without ash.

ash/shell/content_client/shell_browser_main_parts.cc

Index: ash/shell/content_client/shell_browser_main_parts.cc
===================================================================
--- ash/shell/content_client/shell_browser_main_parts.cc	(revision 132861)
+++ ash/shell/content_client/shell_browser_main_parts.cc	(working copy)
@@ -52,13 +52,6 @@
     return true;
   }
 
-  views::NativeWidgetHelperAura* CreateNativeWidgetHelper(
-      views::NativeWidgetAura* native_widget) OVERRIDE {
-    // The default behavior of the test delegate is to work in desktop
-    // mode. Return NULL here so NativeWidgetAura uses our RootWindow instead.
-    return NULL;
-  }
-
  private:
   DISALLOW_COPY_AND_ASSIGN(ShellViewsDelegate);
 };