[MD History] Copy stats from the old history page.

chrome/browser/resources/md_history/constants.js

Index: chrome/browser/resources/md_history/constants.js
diff --git a/chrome/browser/resources/md_history/constants.js b/chrome/browser/resources/md_history/constants.js
index b6e51d49e59f3e63066a57008ab56f851271711e..aa82dbb138f00b2b3a440933cb93f4e6829e162e 100644
--- a/chrome/browser/resources/md_history/constants.js
+++ b/chrome/browser/resources/md_history/constants.js
@@ -21,6 +21,19 @@ var BROWSING_GAP_TIME = 15 * 60 * 1000;
 var TITLE_MAX_LENGTH = 300;
 
 /**
+ * The largest bucket value for UMA histogram, based on entry ID. All entries
+ * with IDs greater than this will be included in this bucket.
+ * @const
+ */
+var UMA_MAX_BUCKET_VALUE = 1000;
+
+/**
+ * The largest bucket value for a UMA histogram that is a subset of above.
+ * @const
+ */
+var UMA_MAX_SUBSET_BUCKET_VALUE = 100;
+
+/**
  * Histogram buckets for UMA tracking of which view is being shown to the user.
  * @enum {number}
  */
@@ -34,6 +47,30 @@ var HistoryViewHistogram = {
 };
 
 /**
+ * @const
+ */
+var SYNCED_TABS_HISTOGRAM_NAME = 'HistoryPage.OtherDevicesMenu';
+
+/**
+ * Histogram buckets for UMA tracking of synced tabs.
+ * @const
+ */
+var SyncedTabsHistogram = {
+  INITIALIZED: 0,
+  SHOW_MENU_DEPRECATED: 1,
+  LINK_CLICKED: 2,
+  LINK_RIGHT_CLICKED_DEPRECATED: 3,

[tsergeant, 2016/08/18 04:14:34]

Why are these deprecated? This one and 'SHOW_SESSION_MENU' seem like they could
still be collected.

[calamity, 2016/08/19 13:59:43]

I suppose I can add these. They just didn't exist back in the old history page
anymore..

Done.

+  SESSION_NAME_RIGHT_CLICKED_DEPRECATED: 4,
+  SHOW_SESSION_MENU_DEPRECATED: 5,
+  COLLAPSE_SESSION: 6,
+  EXPAND_SESSION: 7,
+  OPEN_ALL: 8,
+  HAS_FOREIGN_DATA: 9,
+  HIDE_FOR_NOW: 10,
+  LIMIT: 11  // Should always be the last one.
+};
+
+/**
  * @enum {number}
  */
 var HistoryRange = {