Add metrics for webapk update rate.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/metrics/WebApkUma.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/metrics/WebApkUma.java b/chrome/android/java/src/org/chromium/chrome/browser/metrics/WebApkUma.java
index 1d4204c61e8f5aa8ba661a7b81ee270f1492c8e0..f93b439653b212689a5611c7e6c931b1027c213f 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/metrics/WebApkUma.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/metrics/WebApkUma.java
@@ -90,6 +90,16 @@ public class WebApkUma {
                 "WebApk.Install.GooglePlayInstallResult", result, GOOGLE_PLAY_INSTALL_RESULT_MAX);
     }
 
+    /**
+     * Records whether updating a WebAPK from Google Play succeeded. If not, records the reason
+     * that the update failed.
+     */
+    public static void recordGooglePlayUpdateResult(int result) {
+        assert result >= 0 && result < GOOGLE_PLAY_INSTALL_RESULT_MAX;
+        RecordHistogram.recordEnumeratedHistogram(
+                "WebApk.Update.GooglePlayUpdateResult", result, GOOGLE_PLAY_INSTALL_RESULT_MAX);
+    }
+
     /** Records the duration of a WebAPK session (from launch/foreground to background). */
     public static void recordWebApkSessionDuration(long duration) {
         RecordHistogram.recordLongTimesHistogram(