Add metrics to track Google Play install WebAPK failures.

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 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;
 
+    // This enum is used to back UMA histograms, and should therefore be treated as append-only.
+    public static final int GOOGLE_PLAY_INSTALL_SUCCESS = 0;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_NO_DELEGATE = 1;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_TO_CONNECT_TO_SERVICE = 2;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_CALLER_VERIFICATION_FAILURE = 3;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_POLICY_VIOLATION = 4;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_API_DISABLED = 5;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_REQUEST_FAILED = 6;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_DOWNLOAD_CANCELLED = 7;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_DOWNLOAD_ERROR = 8;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_INSTALL_ERROR = 9;
+    public static final int GOOGLE_PLAY_INSTALL_FAILED_INSTALL_TIMEOUT = 10;
+    public static final int GOOGLE_PLAY_INSTALL_RESULT_MAX = 11;
+
     public static final String HISTOGRAM_UPDATE_REQUEST_SENT =
             "WebApk.Update.RequestSent";
 
     public static final String HISTOGRAM_UPDATE_REQUEST_QUEUED = "WebApk.Update.RequestQueued";
 
+    public static final String HISTOGRAM_GOOGLE_PLAY_INSTALL_RESULT =
+            "WebApk.Install.GooglePlayInstallResult";
+
     private static final int WEBAPK_OPEN_MAX = 3;
     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;
 
     /**
      * 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) {
@@ skipping 14 matching lines @@
 
     /**
      * 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(int type) {
         assert type >= 0 && type < WEBAPK_OPEN_MAX;
         RecordHistogram.recordEnumeratedHistogram("WebApk.OpenFromMenu", type, WEBAPK_OPEN_MAX);
     }
+
+    /**
+     * Records whether installing WebAPKs from Google Play succeeded. If not, records the reason of
+     * failures sent by Google Play.

[pkotwicz, 2017/03/21 16:59:39]

Nit: "the reason of failures" -> "the failure reason"

"the reason that the install failed" is also OK

[Xi Han, 2017/03/21 18:43:45]

Done.

+     */
+    public static void recordGooglePlayIntallResult(int result) {
+        assert result >= 0 && result < GOOGLE_PLAY_INSTALL_RESULT_MAX;
+        RecordHistogram.recordEnumeratedHistogram(
+                HISTOGRAM_GOOGLE_PLAY_INSTALL_RESULT, result, GOOGLE_PLAY_INSTALL_RESULT_MAX);

[pkotwicz, 2017/03/21 16:59:39]

Nit: You can just inline the histogram name
("WebApk.Install.GooglePlayInstallResult")

[Xi Han, 2017/03/21 18:43:45]

Done.

+    }
 }