Create LegacyExternalAuthUtils

* Create LegacyExternalAuthUtils and related classes, which
  are empty subclasses of the ExternalAuthUtils classes. These will be
  referenced downstream temporarily while ExternalAuthUtils is moved to
  //components.
* Create empty new target //components/externalauth/android:java so we
  can add the downstream dependency before the migration.

This is patch 2/6 for refactoring ExternalAuthUtils into //components.

Bug: 1144858
Change-Id: I928ee2998f7042c85e64d8e91e275d23b789fc79
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2568689
Commit-Queue: Nick Burris <nburris@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Peter Conn <peconn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#835776}

chrome/browser/android/externalauth/BUILD.gn

@@ -16,6 +16,9 @@ android_library("java") {
   ]
   sources = [
     "java/src/org/chromium/chrome/browser/externalauth/ExternalAuthUtils.java",
+    "java/src/org/chromium/chrome/browser/externalauth/LegacyExternalAuthUtils.java",
+    "java/src/org/chromium/chrome/browser/externalauth/LegacyUserRecoverableErrorHandler.java",
+    "java/src/org/chromium/chrome/browser/externalauth/LegacyVerifiedHandler.java",
     "java/src/org/chromium/chrome/browser/externalauth/UserRecoverableErrorHandler.java",
     "java/src/org/chromium/chrome/browser/externalauth/VerifiedHandler.java",
   ]

chrome/browser/android/externalauth/java/src/org/chromium/chrome/browser/externalauth/LegacyExternalAuthUtils.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.externalauth;
+
+/**
+ * Temporary class, identical to {@link ExternalAuthUtils}, for migration.
+ *
+ * This class will be referenced temporarily while ExternalAuthUtils is moved to components.
+ *
+ * TODO(crbug.com/1144858): Remove this class after downstream uses
+ * components.externalauth.ExternalAuthUtils.
+ */
+public class LegacyExternalAuthUtils extends ExternalAuthUtils {
+    public boolean canUseGooglePlayServices(final LegacyUserRecoverableErrorHandler errorHandler) {
+        return super.canUseGooglePlayServices(errorHandler);
+    }
+
+    public boolean canUseFirstPartyGooglePlayServices(
+            LegacyUserRecoverableErrorHandler userRecoverableErrorHandler) {
+        return super.canUseFirstPartyGooglePlayServices(userRecoverableErrorHandler);
+    }
+}

chrome/browser/android/externalauth/java/src/org/chromium/chrome/browser/externalauth/LegacyUserRecoverableErrorHandler.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.externalauth;
+
+import android.content.Context;
+
+/**
+ * Temporary class, identical to {@link UserRecoverableErrorHandler}, for migration.
+ *
+ * This class will be referenced temporarily while UserRecoverableErrorHandler is moved to
+ * components.
+ *
+ * TODO(crbug.com/1144858): Remove this class after downstream uses
+ * components.externalauth.UserRecoverableErrorHandler.
+ */
+public abstract class LegacyUserRecoverableErrorHandler extends UserRecoverableErrorHandler {
+    public static final class Silent extends LegacyUserRecoverableErrorHandler {
+        @Override
+        protected final void handle(final Context context, final int errorCode) {}
+    }
+}

chrome/browser/android/externalauth/java/src/org/chromium/chrome/browser/externalauth/LegacyVerifiedHandler.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.externalauth;
+
+import android.content.Context;
+
+/**
+ * Temporary class, identical to {@link VerifiedHandler}, for migration.
+ *
+ * This class will be referenced temporarily while VerifiedHandler is moved to components.
+ *
+ * TODO(crbug.com/1144858): Remove this class after downstream uses
+ * components.externalauth.VerifiedHandler.
+ */
+public class LegacyVerifiedHandler extends VerifiedHandler {
+    public LegacyVerifiedHandler(
+            Context context, LegacyExternalAuthUtils externalAuthUtils, int authRequirements) {
+        super(context, externalAuthUtils, authRequirements);
+    }
+}

components/externalauth/android/BUILD.gn

+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+java_group("java") {
+  # Temporary empty target for migrating downstream dependency.
+}

components/externalauth/android/DIR_METADATA

+monorail {
+  component: "Internals>Core"
+}
+os: ANDROID

components/externalauth/android/OWNERS

+peconn@chromium.org
+eirage@chromium.org

components/externalauth/android/README

+The externalauth component provides utilities for external authentication, such
+as whether the current Chrome build is Google-signed, or whether Google Play
+Services is available. ExternalAuthUtils is the main class of the component, and
+the other classes are helpers used by ExternalAuthUtils and its callers.