Bug 1097876 - Collect UITelemetry about the Panic Button, r=florian.

browser/components/customizableui/CustomizableWidgets.jsm

@@ -10,6 +10,8 @@ this.EXPORTED_SYMBOLS = ["CustomizableWidgets"];
 Cu.import("resource:///modules/CustomizableUI.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "BrowserUITelemetry",
+  "resource:///modules/BrowserUITelemetry.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
   "resource://gre/modules/PlacesUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "PlacesUIUtils",
@@ -1012,6 +1014,7 @@ if (Services.prefs.getBoolPref("privacy.panicButton.enabled")) {
       this._ensureSanitizer();
       this._sanitizer.range = this._getSanitizeRange(doc);
       let group = doc.getElementById("PanelUI-panic-timeSpan");
+      BrowserUITelemetry.countPanicEvent(group.selectedItem.id);
       group.selectedItem = doc.getElementById("PanelUI-panic-5min");
       let itemsToClear = [
         "cookies", "history", "openWindows", "formdata", "sessions", "cache", "downloads"

browser/modules/BrowserUITelemetry.jsm

@@ -599,6 +599,10 @@ this.BrowserUITelemetry = {
     this._countEvent(["click-builtin-item", source, "search-settings"]);
   },
 
+  countPanicEvent: function(timeId) {
+    this._countEvent(["forget-button", timeId]);
+  },
+
   _logAwesomeBarSearchResult: function (url) {
     let spec = Services.search.parseSubmissionURL(url);
     if (spec.engine) {