Correctly enable WebAPK updates when "installation from unknown sources" is disabled

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

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
index 6db25e2016efbb497e3e62af568353c456e51fa7..d81f1d27073baa068348b83d2a61e319abcc8121 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/ChromeWebApkHost.java
@@ -47,6 +47,17 @@ public class ChromeWebApkHost {
         return isEnabledInPrefs();
     }
 
+    // Returns whether updating the WebAPK is enabled.
+    public static boolean areUpdatesEnabled() {
+        if (!isEnabled()) return false;
+
+        // Updating a WebAPK without going through Google Play requires "installation from unknown
+        // sources" to be enabled. It is confusing for a user to see a dialog asking them to enable
+        // "installation from unknown sources" when they are in the middle of using the WebAPK (as
+        // opposed to after requesting to add a WebAPK to the homescreen).
+        return installingFromUnknownSourcesAllowed() || canUseGooglePlayToInstallWebApk();
+    }
+
     /** Return whether installing WebAPKs using Google Play is enabled. */
     public static boolean canUseGooglePlayToInstallWebApk() {
         if (!isEnabled()) return false;