Bug 1266163 - Replace FENNEC_READER_VIEW_BUTTON histogram with UI telemetry. r=mfinkle,barbara

MozReview-Commit-ID: 1guxvXp6loC

--HG--
extra : rebase_source : a474fb10ef8e197313debb970640f1243b2dfca1

mobile/android/chrome/content/Reader.js

@@ -22,19 +22,6 @@ var Reader = {
     return this._hasUsedToolbar = Services.prefs.getBoolPref("reader.has_used_toolbar");
   },
 
-  get _buttonHistogram() {
-    delete this._buttonHistogram;
-    return this._buttonHistogram = Services.telemetry.getHistogramById("FENNEC_READER_VIEW_BUTTON");
-  },
-
-  // Values for "FENNEC_READER_VIEW_BUTTON" histogram.
-  _buttonHistogramValues: {
-    HIDDEN: 0,
-    SHOWN: 1,
-    TAP_ENTER: 2,
-    TAP_EXIT: 3
-  },
-
   /**
    * BackPressListener (listeners / ReaderView Ids).
    */
@@ -166,9 +153,9 @@ var Reader = {
     readerModeCallback: function(browser) {
       let url = browser.currentURI.spec;
       if (url.startsWith("about:reader")) {
-        Reader._buttonHistogram.add(Reader._buttonHistogramValues.TAP_EXIT);
+        UITelemetry.addEvent("action.1", "button", "reader_exit");
       } else {
-        Reader._buttonHistogram.add(Reader._buttonHistogramValues.TAP_ENTER);
+        UITelemetry.addEvent("action.1", "button", "reader_enter");
       }
       browser.messageManager.sendAsyncMessage("Reader:ToggleReaderMode");
     },
@@ -207,9 +194,9 @@ var Reader = {
 
     if (browser.isArticle) {
       showPageAction("drawable://reader", Strings.reader.GetStringFromName("readerView.enter"));
-      this._buttonHistogram.add(this._buttonHistogramValues.SHOWN);
+      UITelemetry.addEvent("show.1", "button", "reader_available");
     } else {
-      this._buttonHistogram.add(this._buttonHistogramValues.HIDDEN);
+      UITelemetry.addEvent("show.1", "button", "reader_unavailable");
     }
   },
 

toolkit/components/telemetry/Histograms.json

@@ -9476,13 +9476,6 @@
     "n_values": 5,
     "description": "The result of trying to download a document to show in reader view (0=Success, 1=Error XHR, 2=Error no document)"
   },
-  "FENNEC_READER_VIEW_BUTTON" : {
-    "expires_in_version": "50",
-    "alert_emails": ["mobile-frontend@mozilla.com"],
-    "kind": "enumerated",
-    "n_values": 10,
-    "description": "Bug 1219240: Measures user interaction with the reader view button (0=Button hidden, 1=Button shown, 2=Tap to enter reader view, 3=Tap to exit reader view, 4=Long tap)"
-  },
   "FENNEC_LOAD_SAVED_PAGE": {
     "expires_in_version": "50",
     "alert_emails": ["mobile-frontend@mozilla.com"],