Add an activity that allows whitelisted applications to clear all data in Chrome.

chrome/android/java/res/values-v17/styles.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2014 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. -->
 
 <resources>
     <!-- A theme for alert dialogs. The colors are copied from MainTheme, and the window
          dimensions are copied from *.MinWidth theme variants. Sadly there is no
          AppCompat.Light.Dialog.Alert or even AppCompat.Light.Dialog.MinWidth. -->
     <style name="AlertDialogTheme" parent="Theme.AppCompat.Light.Dialog">
@@ skipping 241 matching lines @@
         name="RemoteNotificationProgressBar"
         parent="@android:style/Widget.Holo.ProgressBar.Horizontal"/>
     <style name="CastMediaRouteButton" parent="@style/Widget.MediaRouter.MediaRouteButton">
         <item name="android:background">@null</item>
         <item name="android:paddingTop">0dp</item>
         <item name="android:paddingBottom">0dp</item>
         <item name="android:paddingStart">0dp</item>
         <item name="android:paddingEnd">0dp</item>
         <item name="externalRouteEnabledDrawable">@drawable/ic_cast_dark_chrome</item>
     </style>
-    
+
+    <!-- Transparent -->
+    <style name="TransparentBase" parent="Theme.AppCompat">
+        <item name="android:windowBackground">@android:color/transparent</item>
+        <item name="android:windowContentOverlay">@null</item>
+        <item name="android:windowIsTranslucent">true</item>
+        <item name="android:windowNoTitle">true</item>
+    </style>
+    <style name="Transparent" parent="@style/TransparentBase" />
+
 </resources>