Let Chrome app handle Ash accelerators first if the app is launched as a window

ash/test/test_shell_delegate.cc

Index: ash/test/test_shell_delegate.cc
diff --git a/ash/test/test_shell_delegate.cc b/ash/test/test_shell_delegate.cc
index f3dbea53826874b68214448b1685872bb8c7e175..7a9f2fbf8fc2183af132175d0acdec304e236c6f 100644
--- a/ash/test/test_shell_delegate.cc
+++ b/ash/test/test_shell_delegate.cc
@@ -47,6 +47,10 @@ void TestShellDelegate::Exit() {
 void TestShellDelegate::NewWindow(bool incognito) {
 }
 
+bool TestShellDelegate::IsBrowserWindow(const aura::Window* window) {
+  return false;
+}
+
 void TestShellDelegate::Search() {
 }