Add InfoBar delegate for previews

chrome/browser/previews/previews_infobar_delegate.h

+// Copyright 2016 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_PREVIEWS_PREVIEWS_INFOBAR_DELEGATE_H_
+#define CHROME_BROWSER_PREVIEWS_PREVIEWS_INFOBAR_DELEGATE_H_
+
+#include "components/infobars/core/confirm_infobar_delegate.h"
+
+namespace content {
+class WebContents;
+}
+
+// Shows an infobar that lets the user know that a preview page has been loaded,
+// and gives the user a link to reload the original page. This infobar will only
+// be shown once per page load. Records uma data for user interactions with the

[bengr, 2016/08/31 23:37:34]

uma -> UMA

[megjablon, 2016/09/08 00:25:45]

Done.

+// infobar.
+class PreviewsInfoBarDelegate : public ConfirmInfoBarDelegate {
+ public:
+  // The type of the infobar. It controls the strings and what UMA data is
+  // recorded for the infobar.
+  enum PreviewsInfoBarType {
+    LOFI,      // Server-side image replacement.
+    LITE_PAGE, // Server-side page rewrite.
+    OFFLINE,   // Offline copy of the page.
+  };
+
+  ~PreviewsInfoBarDelegate() override;
+
+  // Creates a preview infobar and corresponding delegate and adds the infobar
+  // to InfoBarService.
+  static void Create(content::WebContents* web_contents,
+                     PreviewsInfoBarType infobar_type);
+
+ private:
+  PreviewsInfoBarDelegate(content::WebContents* web_contents,
+                          PreviewsInfoBarType infobar_type);
+
+  // ConfirmInfoBarDelegate overrides:
+  infobars::InfoBarDelegate::InfoBarIdentifier GetIdentifier() const override;
+  int GetIconId() const override;
+  bool ShouldExpire(const NavigationDetails& details) const override;
+  base::string16 GetMessageText() const override;
+  int GetButtons() const override;
+  base::string16 GetLinkText() const override;
+  bool LinkClicked(WindowOpenDisposition disposition) override;
+
+  PreviewsInfoBarType infobar_type_;
+
+  DISALLOW_COPY_AND_ASSIGN(PreviewsInfoBarDelegate);
+};
+
+#endif  // CHROME_BROWSER_PREVIEWS_PREVIEWS_INFOBAR_DELEGATE_H_