[Android]: Hide add-to-homescreen app menu item when WebAPK is installed

chrome/android/java/src/org/chromium/chrome/browser/metrics/WebApkUma.java

 // Copyright 2017 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.
 
 package org.chromium.chrome.browser.metrics;
 
+import android.support.annotation.IntDef;
+
 import org.chromium.base.metrics.RecordHistogram;
 
 /**
  * Centralizes UMA data collection for WebAPKs. NOTE: Histogram names and values are defined in
  * tools/metrics/histograms/histograms.xml. Please update that file if any change is made.
  */
 public class WebApkUma {
     // This enum is used to back UMA histograms, and should therefore be treated as append-only.
     public static final int UPDATE_REQUEST_SENT_FIRST_TRY = 0;
     public static final int UPDATE_REQUEST_SENT_ONSTOP = 1;
     public static final int UPDATE_REQUEST_SENT_WHILE_WEBAPK_IN_FOREGROUND = 2;
     public static final int UPDATE_REQUEST_SENT_MAX = 3;
 
     // This enum is used to back UMA histograms, and should therefore be treated as append-only.
     // The queued request times shouldn't exceed three.
     public static final int UPDATE_REQUEST_QUEUED_ONCE = 0;
     public static final int UPDATE_REQUEST_QUEUED_TWICE = 1;
     public static final int UPDATE_REQUEST_QUEUED_THREE_TIMES = 2;
     public static final int UPDATE_REQUEST_QUEUED_MAX = 3;
 
     public static final String HISTOGRAM_UPDATE_REQUEST_SENT =
             "WebApk.Update.RequestSent";
 
     public static final String HISTOGRAM_UPDATE_REQUEST_QUEUED = "WebApk.Update.RequestQueued";
 
+    // This enum is used to back UMA histograms, and should therefore be treated as append-only.
+    @IntDef({WEBAPK_OPEN_LAUNCH_SUCCESS, WEBAPK_OPEN_NO_LAUNCH_INTENT,
+            WEBAPK_OPEN_ACTIVITY_NOT_FOUND})
+    public @interface WebApkOpenResult {}
+    public static final int WEBAPK_OPEN_LAUNCH_SUCCESS = 0;
+    public static final int WEBAPK_OPEN_NO_LAUNCH_INTENT = 1;
+    public static final int WEBAPK_OPEN_ACTIVITY_NOT_FOUND = 2;
+    public static final int WEBAPK_OPEN_MAX = 3;
+
     /**
      * Records the time point when a request to update a WebAPK is sent to the WebAPK Server.
      * @param type representing when the update request is sent to the WebAPK server.
      */
     public static void recordUpdateRequestSent(int type) {

[nyquist, 2017/02/28 18:19:17]

While you're at it, would you want to do the @IntDef trick here too?

[gonzalon, 2017/02/28 20:46:04]

Done.

         assert type >= 0 && type < UPDATE_REQUEST_SENT_MAX;
         RecordHistogram.recordEnumeratedHistogram(HISTOGRAM_UPDATE_REQUEST_SENT,
                 type, UPDATE_REQUEST_SENT_MAX);
     }
 
     /**
      * Records the times that an update request has been queued once, twice and three times before
      * sending to WebAPK server.
      * @param times representing the times that an update has been queued.
      */
     public static void recordUpdateRequestQueued(int times) {
         RecordHistogram.recordEnumeratedHistogram(HISTOGRAM_UPDATE_REQUEST_QUEUED, times,
                 UPDATE_REQUEST_QUEUED_MAX);
     }
+
+    /**
+     * When a user presses on the "Open WebAPK" menu item, this records whether the WebAPK was
+     * opened successfully.
+     * @param type Result of trying to open WebAPK.
+     */
+    public static void recordWebApkOpenAttempt(@WebApkOpenResult int type) {
+        assert type >= 0 && type < WEBAPK_OPEN_MAX;

[nyquist, 2017/02/28 18:19:17]

I'm not sure this is technically necessary now, but feel free to keep it for
your own sanity, and clarity :-)

[gonzalon, 2017/02/28 20:46:04]

Done.

+        RecordHistogram.recordEnumeratedHistogram("WebApk.OpenFromMenu", type, WEBAPK_OPEN_MAX);
+    }
 }