Add an infobar if a session is being controlled by an automated test.

chrome/browser/ui/startup/automation_infobar_delegate.h

Index: chrome/browser/ui/startup/automation_infobar_delegate.h
diff --git a/chrome/browser/ui/startup/automation_infobar_delegate.h b/chrome/browser/ui/startup/automation_infobar_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..bf60e2f422e52ab4346eb54f811777dc5b61f06b
--- /dev/null
+++ b/chrome/browser/ui/startup/automation_infobar_delegate.h
@@ -0,0 +1,33 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_STARTUP_AUTOMATION_INFOBAR_DELEGATE_H_
+#define CHROME_BROWSER_UI_STARTUP_AUTOMATION_INFOBAR_DELEGATE_H_
+
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "base/strings/string16.h"
+#include "components/infobars/core/confirm_infobar_delegate.h"
+#include "ui/gfx/vector_icons_public.h"
+#include "url/gurl.h"
+
+// An infobar to inform users if their browser is being controlled by an
+// automated test.
+class AutomationInfoBarDelegate : public ConfirmInfoBarDelegate {
+ public:
+  static void Create();
+
+ private:
+  AutomationInfoBarDelegate();
+  ~AutomationInfoBarDelegate() override;
+
+  infobars::InfoBarDelegate::InfoBarIdentifier GetIdentifier() const override;
+  bool ShouldExpire(const NavigationDetails& details) const override;
+  base::string16 GetMessageText() const override;
+  int GetButtons() const override;
+
+  DISALLOW_COPY_AND_ASSIGN(AutomationInfoBarDelegate);
+};
+
+#endif  // CHROME_BROWSER_UI_STARTUP_AUTOMATION_INFOBAR_DELEGATE_H_