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..2c3c3052188c312a8ed47a20df4ffa5a7bc3bf4e 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;
@@ -22,6 +23,7 @@ import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.AsyncTask;
+import android.support.annotation.NonNull;
 import android.text.TextUtils;
 import android.util.Base64;
 
@@ -34,6 +36,7 @@ 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.WebappActivity;
 import org.chromium.chrome.browser.webapps.WebappAuthenticator;
 import org.chromium.chrome.browser.webapps.WebappDataStorage;
@@ -45,6 +48,7 @@ import org.chromium.ui.widget.Toast;
 import org.chromium.webapk.lib.client.WebApkValidator;
 
 import java.io.ByteArrayOutputStream;
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -648,5 +652,50 @@ public class ShortcutHelper {
         return null;
     }
 
+    /**
+     * Fetches the information of all WebAPKs installed on the device and returns them to the
+     * caller using a callback.

[pkotwicz, 2017/01/19 19:37:16]

Nit: "installed on the device" -> "installed"

I think that "on the device" is redundant. Shorter comments are easier to read
:)

[gonzalon, 2017/01/19 23:50:16]

Done.

+     *
+     * @param callbackPointer Callback to be called with the information on the WebAPKs found.

[pkotwicz, 2017/01/19 19:37:16]

Nit: "to be called" -> "to call"

[gonzalon, 2017/01/19 23:50:16]

Done.

+     */
+    @CalledByNative
+    public static void listWebApks(long callbackPointer) {
+        List<String> shortNames = new ArrayList<>();
+        List<String> packageNames = new ArrayList<>();
+        List<Integer> shellApkVersions = new ArrayList<>();
+        List<Integer> versionCodes = new ArrayList<>();
+
+        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.

[pkotwicz, 2017/01/19 19:37:16]

How about: "Pass non-null URL parameter so that {@link WebApkInfo#create()}
return value is non-null."

[gonzalon, 2017/01/19 23:50:16]

Done.

+                WebApkInfo webApkInfo =
+                        WebApkInfo.create(packageInfo.packageName, "", ShortcutSource.UNKNOWN);
+                if (webApkInfo != null) {
+                    shortNames.add(webApkInfo.shortName());
+                    packageNames.add(packageInfo.packageName);

[pkotwicz, 2017/01/19 19:37:16]

Nit: packageInfo.packageName -> webApkInfo.webApkPackageName()

[gonzalon, 2017/01/19 23:50:16]

Done.

+                    shellApkVersions.add(webApkInfo.shellApkVersion());
+                    versionCodes.add(packageInfo.versionCode);
+                }
+            }
+        }
+        nativeOnWebApksFound(callbackPointer, shortNames.toArray(new String[0]),
+                packageNames.toArray(new String[0]), integerListToIntArray(shellApkVersions),
+                integerListToIntArray(versionCodes));
+    }
+
+    private static int[] integerListToIntArray(@NonNull List<Integer> list) {
+        int[] array = new int[list.size()];
+        int i = 0;
+        for (Integer value : list) {
+            array[i++] = value;
+        }
+        return array;
+    }
+
     private static native void nativeOnWebappDataStored(long callbackPointer);
+    private static native void nativeOnWebApksFound(long callbackPointer, String[] shortNames,
+            String[] packageName, int[] shellApkVersions, int[] versionCodes);
 }