Adds the MostVisitedAction stat. This stat will provide a baseline to compare

chrome/browser/ui/webui/ntp/ntp_stats.h

Index: chrome/browser/ui/webui/ntp/ntp_stats.h
===================================================================
--- chrome/browser/ui/webui/ntp/ntp_stats.h	(revision 0)
+++ chrome/browser/ui/webui/ntp/ntp_stats.h	(revision 0)
@@ -0,0 +1,26 @@
+// Copyright (c) 2012 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_WEBUI_NTP_NTP_STATS_H_
+#define CHROME_BROWSER_UI_WEBUI_NTP_NTP_STATS_H_
+#pragma once
+
+// This enum is also defined in histograms.xml. These values represent the
+// action that the user has taken to leave the NTP. This is shared between the
+// Suggested pane and the Most Visited pane. This is also defined in new_tab.js.
+enum NtpFollowAction {
+  // Values 0 to 10 are the core values from PageTransition (see
+  // page_transition_types.h).
+
+  // The user has clicked on a tile.
+  NTP_FOLLOW_ACTION_CLICKED_TILE = 11,
+  // The user has moved to another pane within the NTP.
+  NTP_FOLLOW_ACTION_CLICKED_OTHER_NTP_PANE,
+  // Any action other than what is listed here (e.g. closing the tab, etc.).
+  NTP_FOLLOW_ACTION_OTHER,
+  // The number of suggested sites actions that we log.
+  NUM_NTP_FOLLOW_ACTIONS
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_NTP_NTP_STATS_H_