Remove redundancy in security interstitial UMA logic

chrome/browser/interstitials/security_interstitial_uma_helper.h

+// Copyright (c) 2014 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_INTERSTITIALS_SECURITY_INTERSTITIAL_UMA_HELPER_H_
+#define CHROME_BROWSER_INTERSTITIALS_SECURITY_INTERSTITIAL_UMA_HELPER_H_
+
+#include "base/task/cancelable_task_tracker.h"
+#include "base/time/time.h"
+#include "url/gurl.h"
+
+namespace content {
+class WebContents;
+}
+
+namespace extensions {
+class ExperienceSamplingEvent;
+}
+
+// Most of the security interstitials share a common layout and set of
+// choices. SecurityInterstitialUmaHelper is intended to help the security
+// interstitials record user choices in a common way via UMA histograms.
+class SecurityInterstitialUmaHelper {
+ public:
+  // These enums are used for histograms.  Don't reorder, delete, or insert
+  // elements. New elements should be added at the end (right before the max).
+  enum SecurityInterstitialDecision {
+    SHOW,
+    PROCEED,
+    DONT_PROCEED,
+    PROCEEDING_DISABLED,
+    MAX_DECISION
+  };
+  enum SecurityInterstitialInteraction {
+    TOTAL_VISITS,
+    SHOW_ADVANCED,
+    SHOW_PRIVACY_POLICY,
+    SHOW_DIAGNOSTIC,
+    SHOW_LEARN_MORE,
+    RELOAD,
+    OPEN_TIME_SETTINGS,
+    MAX_INTERACTION
+  };
+
+  SecurityInterstitialUmaHelper(content::WebContents* web_contents,
+                                const GURL& url,
+                                const std::string& histogram_prefix,
+                                const std::string& sampling_event_name);
+  ~SecurityInterstitialUmaHelper();
+
+  // Record a user decision or interaction to the appropriate UMA histogram.
+  void RecordUserDecision(SecurityInterstitialDecision decision);
+  void RecordUserInteraction(SecurityInterstitialInteraction interaction);
+
+ private:
+  // Used to query the HistoryService to see if the URL is in history.
+  void OnGotHistoryCount(bool success, int num_visits, base::Time first_visit);
+
+  content::WebContents* web_contents_;
+  const GURL request_url_;
+  const std::string histogram_prefix_;
+  const std::string sampling_event_name_;
+  int num_visits_;
+  base::CancelableTaskTracker request_tracker_;
+#if defined(ENABLE_EXTENSIONS)
+  scoped_ptr<extensions::ExperienceSamplingEvent> sampling_event_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(SecurityInterstitialUmaHelper);
+};
+
+#endif  // CHROME_BROWSER_INTERSTITIALS_SECURITY_INTERSTITIAL_UMA_HELPER_H_