Add metrics to track Google Play install WebAPK failures.

chrome/android/java/src/org/chromium/chrome/browser/webapps/GooglePlayWebApkInstallDelegate.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/GooglePlayWebApkInstallDelegate.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/GooglePlayWebApkInstallDelegate.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/GooglePlayWebApkInstallDelegate.java
index 87a5bf68d3509f06787a7c05ae2ce4af2b8e7b7e..7de2c2403bec3982e00e2728941270eaa7f9ccf9 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/GooglePlayWebApkInstallDelegate.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/GooglePlayWebApkInstallDelegate.java
@@ -44,6 +44,17 @@ public interface GooglePlayWebApkInstallDelegate {
             Callback<Integer> callback);
 
     /**
+     * Uses Google Play to update WebAPK asynchronously.
+     * @param packageName The package name of WebAPK to update.
+     * @param version The version of WebAPK to update.
+     * @param title The title of the WebAPK to display during update.
+     * @param token The token from WebAPK Minter Server.
+     * @param url The start URL of the WebAPK to update.
+     * @param callback The callback to invoke when the update completes, times out or fails.
+     */
+    void updateAsync(String packageName, int version, String title, String token, String url,
+            Callback<Integer> callback);

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

This is already in ToT :)

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

Oh, yes, I didn't rebase it in time. It won't be in the new change patch.

+    /**
      * Calls the callback once the installation either succeeded or failed.
      * @param packageName The package name of WebAPK for the installation.
      * @param event The result of the install.