Created the dialog offering the user to merge their account data or keep it

chrome/android/java/src/org/chromium/chrome/browser/signin/AccountSigninActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/signin/AccountSigninActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/signin/AccountSigninActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/signin/AccountSigninActivity.java
new file mode 100644
index 0000000000000000000000000000000000000000..2b286cc13624f88cdfb1dacf0c2161f3bb568124
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/signin/AccountSigninActivity.java
@@ -0,0 +1,106 @@
+// Copyright 2016 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.signin;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+import android.view.LayoutInflater;
+
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.firstrun.ProfileDataCache;
+import org.chromium.chrome.browser.preferences.Preferences;
+import org.chromium.chrome.browser.preferences.PreferencesLauncher;
+import org.chromium.chrome.browser.profiles.Profile;
+import org.chromium.chrome.browser.sync.ui.ConfirmImportSyncDataFragment;
+import org.chromium.chrome.browser.sync.ui.ConfirmImportSyncDataFragment.Listener;
+import org.chromium.chrome.browser.sync.ui.SyncCustomizationFragment;
+
+/**
+ * An Activity displayed from the MainPreferences to allow the user to pick an account to
+ * sign in to.
+ */
+public class AccountSigninActivity extends AppCompatActivity
+        implements AccountSigninView.Listener, SigninManager.SignInCallback{
+    private static final String TAG = "AccountSigninFragment";
+
+    private static final String CONFIRM_IMPORT_SYNC_DATA_DIALOG_TAG =
+            "signin_import_data_tag";
+
+    private AccountSigninView mView;
+    private String mAccountName;
+    private boolean mShowSyncSettings = false;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        mView = (AccountSigninView) LayoutInflater.from(this).inflate(
+                R.layout.account_signin_view, null);
+        mView.init(new ProfileDataCache(this, Profile.getLastUsedProfile()));
+        mView.setListener(this);
+
+        setContentView(mView);
+    }
+
+    @Override
+    public void onAccountSelectionCanceled() {
+        finish();
+    }
+
+    @Override
+    public void onNewAccount() {
+        AccountAdder.getInstance().addAccount(this, AccountAdder.ADD_ACCOUNT_RESULT);
+    }
+
+    @Override
+    public void onAccountSelected(String accountName) {
+        mAccountName = accountName;
+
+    }
+
+    @Override
+    public void onDoneClicked() {
+        SigninManager.get(this).signIn(mAccountName, null, this);
+    }
+
+    @Override
+    public void onSettingsClicked() {
+        mShowSyncSettings = true;
+        SigninManager.get(this).signIn(mAccountName, null, this);
+    }
+
+    @Override
+    public void onFailedToSetForcedAccount(String forcedAccountName) {
+        assert false : "No forced accounts in account switching preferences.";
+
+    }
+
+    @Override
+    public void onSignInComplete() {
+        if (mShowSyncSettings) {
+            Intent intent = PreferencesLauncher.createIntentForSettingsPage(this,
+                    SyncCustomizationFragment.class.getName());
+            Bundle args = new Bundle();
+            args.putString(SyncCustomizationFragment.ARGUMENT_ACCOUNT, mAccountName);
+            intent.putExtra(Preferences.EXTRA_SHOW_FRAGMENT_ARGUMENTS, args);
+            startActivity(intent);
+        }
+
+        finish();
+    }
+
+    @Override
+    public void onSignInAborted() {
+        assert false : "Signin cannot be aborted when forced.";
+    }
+
+    @Override
+    public void onPreviousAccountFound(
+            String oldAccountName, String newAccountName, Listener callback) {
+        ConfirmImportSyncDataFragment.showNewInstance(
+                oldAccountName, newAccountName, getFragmentManager(), callback);
+    }
+}