Revert "Rename U2f* to Fido2*"

This reverts commit 203117d9.

Reason for revert: broke downstream and official builders. Builder:
http://uberchromegw/i/official.android/builders/official-arm/builds/3216

Original change's description:
> Rename U2f* to Fido2*
> 
> In GmsCore v19, the Fido2 APIs will provide the unified functionality
> of the U2F and Fido2 APIs so it will no longer be necessary to call
> both of them.
> 
> Since the rename spans upstream and downstream, will initially add
> all Fido2* classes and then later remove the U2f* classes once
> downstream changes have landed.
> 
> Bug: 842006
> Change-Id: I4775682b428c0ffdc4aa6f699136a2c7d15ee40c
> Reviewed-on: https://chromium-review.googlesource.com/1054778
> Reviewed-by: Maria Khomenko <mariakhomenko@chromium.org>
> Commit-Queue: Kim Paulhamus <kpaulhamus@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#558479}

TBR=mariakhomenko@chromium.org,kpaulhamus@chromium.org

Change-Id: I20e10d48e1630d8a084003287f2dda9365d030be
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 843011, 842006
Reviewed-on: https://chromium-review.googlesource.com/1059595Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558680}

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

@@ -47,7 +47,7 @@ import org.chromium.chrome.browser.sync.GmsCoreSyncListener;
 import org.chromium.chrome.browser.tab.AuthenticatorNavigationInterceptor;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.webapps.GooglePlayWebApkInstallDelegate;
-import org.chromium.chrome.browser.webauth.Fido2ApiHandler;
+import org.chromium.chrome.browser.webauth.U2fApiHandler;
 import org.chromium.components.signin.AccountManagerDelegate;
 import org.chromium.components.signin.SystemAccountManagerDelegate;
 import org.chromium.policy.AppRestrictionsProvider;
@@ -337,9 +337,9 @@ public abstract class AppHooks {
     }
 
     /**
-     * @return a new {@link Fido2ApiHandler} instance.
+     * @return a new {@link U2fApiHandler} instance.
      */
-    public Fido2ApiHandler createFido2ApiHandler() {
-        return new Fido2ApiHandler();
+    public U2fApiHandler createU2fApiHandler() {
+        return new U2fApiHandler();
     }
 }

chrome/android/java/src/org/chromium/chrome/browser/webauth/Fido2ApiHandler.java

-// Copyright 2018 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.webauth;
-
-import org.chromium.base.ThreadUtils;
-import org.chromium.chrome.browser.AppHooks;
-import org.chromium.webauth.mojom.PublicKeyCredentialCreationOptions;
-import org.chromium.webauth.mojom.PublicKeyCredentialRequestOptions;
-
-/**
- * Android implementation of the Authenticator service defined in
- * components/webauth/authenticator.mojom.
- */
-public class Fido2ApiHandler {
-    private static Fido2ApiHandler sInstance;
-
-    /**
-     * @return The Fido2ApiHandler for use during the lifetime of the browser process.
-     */
-    public static Fido2ApiHandler getInstance() {
-        ThreadUtils.checkUiThread();
-        if (sInstance == null) {
-            sInstance = AppHooks.get().createFido2ApiHandler();
-        }
-        return sInstance;
-    }
-
-    protected void makeCredential(
-            PublicKeyCredentialCreationOptions options, HandlerResponseCallback callback) {}
-
-    protected void getAssertion(
-            PublicKeyCredentialRequestOptions options, HandlerResponseCallback callback) {}
-}

chrome/android/java/src/org/chromium/chrome/browser/webauth/U2fApiHandler.java

@@ -27,9 +27,9 @@ public class U2fApiHandler {
         return sInstance;
     }
 
-    protected void makeCredential(
+    protected void u2fRegister(
             PublicKeyCredentialCreationOptions options, HandlerResponseCallback callback) {}
 
-    protected void getAssertion(
+    protected void u2fSign(
             PublicKeyCredentialRequestOptions options, HandlerResponseCallback callback) {}
 }

chrome/android/java_sources.gni

@@ -1404,7 +1404,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/webauth/AuthenticatorFactory.java",
   "java/src/org/chromium/chrome/browser/webauth/AuthenticatorImpl.java",
   "java/src/org/chromium/chrome/browser/webauth/HandlerResponseCallback.java",
-  "java/src/org/chromium/chrome/browser/webauth/Fido2ApiHandler.java",
+  "java/src/org/chromium/chrome/browser/webauth/U2fApiHandler.java",
   "java/src/org/chromium/chrome/browser/webshare/ShareServiceImpl.java",
   "java/src/org/chromium/chrome/browser/webshare/ShareServiceImplementationFactory.java",
   "java/src/org/chromium/chrome/browser/widget/AlertDialogEditText.java",