Add a chrome://webapks page.

chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java b/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
index 9bb166773ac1199ec993a12a54d29685cb851db7..74cf3cfbd67f3a7db760d9fdf8514b1ceaf9a4c8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
@@ -9,6 +9,7 @@ import android.app.ActivityManager;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.ResolveInfo;
@@ -34,6 +35,8 @@ import org.chromium.base.annotations.CalledByNative;
 import org.chromium.blink_public.platform.WebDisplayMode;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.webapps.ChromeWebApkHost;
+import org.chromium.chrome.browser.webapps.WebApkInfo;
+import org.chromium.chrome.browser.webapps.WebApkInfoCallback;
 import org.chromium.chrome.browser.webapps.WebappActivity;
 import org.chromium.chrome.browser.webapps.WebappAuthenticator;
 import org.chromium.chrome.browser.webapps.WebappDataStorage;
@@ -648,5 +651,29 @@ public class ShortcutHelper {
         return null;
     }
 
+    /**
+     * Fetches the information of all WebAPKs installed on the device and returns them to the
+     * caller using a callback.
+     *
+     * @param webApkInfoCallback Callback to be called with each WebAPK found on the device.
+     */
+    public static void listWebApks(WebApkInfoCallback webApkInfoCallback) {
+        PackageManager packageManager = ContextUtils.getApplicationContext().getPackageManager();
+        for (PackageInfo packageInfo : packageManager.getInstalledPackages(0)) {
+            if (WebApkValidator.isValidWebApk(
+                        ContextUtils.getApplicationContext(), packageInfo.packageName)) {
+                // We need to pass in a non-null URL as second parameter to fetch all the
+                // information about the WebAPK.
+                WebApkInfo webApkInfo = WebApkInfo.create(packageInfo.packageName, "", 0);
+                if (webApkInfo != null) {
+                    webApkInfoCallback.onWebApkFound(webApkInfo.shortName(),
+                            packageInfo.packageName, webApkInfo.shellApkVersion(),
+                            packageInfo.versionCode);
+                }
+            }
+        }
+        webApkInfoCallback.destroy();
+    }
+
     private static native void nativeOnWebappDataStored(long callbackPointer);
 }