Removes the dependency to WMTestHelper from app shell.

apps/shell/browser/default_shell_browser_main_delegate.cc

Index: apps/shell/browser/default_shell_browser_main_delegate.cc
diff --git a/apps/shell/browser/default_shell_browser_main_delegate.cc b/apps/shell/browser/default_shell_browser_main_delegate.cc
index e7b2cb8ef2967d6903db4587dd844debe7eca03a..3efabbb36d7f5a88dba923e70a11f74d618a53c3 100644
--- a/apps/shell/browser/default_shell_browser_main_delegate.cc
+++ b/apps/shell/browser/default_shell_browser_main_delegate.cc
@@ -4,6 +4,7 @@
 
 #include "apps/shell/browser/default_shell_browser_main_delegate.h"
 
+#include "apps/shell/browser/shell_desktop_controller.h"
 #include "apps/shell/browser/shell_extension_system.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ -37,4 +38,9 @@ void DefaultShellBrowserMainDelegate::Start(
 void DefaultShellBrowserMainDelegate::Shutdown() {
 }
 
+ShellDesktopController*
+DefaultShellBrowserMainDelegate::CreateDesktopController() {
+  return new ShellDesktopController();
+}
+
 }  // namespace apps