[Android] Add support for a hung renderer dialog

chrome/browser/android/hung_renderer_infobar_delegate.h

+// Copyright 2015 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_ANDROID_HUNG_RENDERER_INFOBAR_DELEGATE_H_
+#define CHROME_BROWSER_ANDROID_HUNG_RENDERER_INFOBAR_DELEGATE_H_
+
+#include "components/infobars/core/confirm_infobar_delegate.h"
+
+namespace content {
+class WebContents;
+}
+
+// A hung renderer infobar is shown when the when the renderer is deemed
+// unresponsive. The infobar provides the user with a choice of either
+// waiting for the renderer to regain responsiveness, or killing the
+// renderer immediately. This class provides the resources necessary to
+// display such an infobar, also logging the action taken by the user
+// (if any) for UMA purposes.
+class HungRendererInfoBarDelegate : public ConfirmInfoBarDelegate {
+ public:
+  // Creates a hung renderer InfoBar, adding it to the InfoBarService
+  // associated with the provided |web_contents|.
+  static void Create(content::WebContents* web_contents);
+
+  // Called if the renderer regains responsiveness before the infobar is
+  // dismissed.
+  void OnRendererResponsive();
+
+ private:
+  // Keep these values in alignment with their histograms.xml counterparts.
+  enum Event {
+    WAIT_CLICKED = 0,
+    KILL_CLICKED,
+    CLOSE_CLICKED,
+    RENDERER_BECAME_RESPONSIVE,
+    INFOBAR_SHUTDOWN,
+    EVENT_COUNT
+  };
+
+  explicit HungRendererInfoBarDelegate(content::WebContents* web_contents);
+  ~HungRendererInfoBarDelegate() override;
+
+  // ConfirmInfoBarDelegate:
+  void InfoBarDismissed() override;
+  HungRendererInfoBarDelegate* AsHungRendererInfoBarDelegate() override;
+  int GetIconID() const override;
+  base::string16 GetMessageText() const override;
+  base::string16 GetButtonLabel(InfoBarButton button) const override;
+  bool Accept() override;
+  bool Cancel() override;
+
+  void LogEvent(Event event);
+
+  content::WebContents* web_contents_;
+
+  bool terminal_event_logged_for_uma_;
+
+  DISALLOW_COPY_AND_ASSIGN(HungRendererInfoBarDelegate);
+};
+
+#endif  // CHROME_BROWSER_ANDROID_HUNG_RENDERER_INFOBAR_DELEGATE_H_