Inherit default text color from MainTheme.

chrome/android/java/res/layout/data_reduction_promo_screen.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2015 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. -->
 
 <org.chromium.chrome.browser.preferences.datareduction.DataReductionPromoView
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:chrome="http://schemas.android.com/apk/res-auto"
     android:background="#c000" >
 
@@ skipping 39 matching lines @@
                         android:id="@+id/text_wrapper"
                         android:layout_height="wrap_content"
                         android:layout_width="wrap_content"
                         android:orientation="vertical" >
 
                         <TextView
                             android:layout_height="wrap_content"
                             android:layout_width="match_parent"
                             android:layout_marginBottom="8dp"
                             android:text="@string/data_reduction_promo_title"
-                            android:textColor="@color/default_text_color"
                             android:textSize="@dimen/data_reduction_promo_title_text_size" />
 
                         <TextView
                             android:layout_height="wrap_content"
                             android:layout_width="match_parent"
                             android:layout_marginBottom="30dp"
                             android:lineSpacingMultiplier="1.3"
                             android:text="@string/data_reduction_promo_summary"
                             android:textColor="#646464"
                             android:textSize="@dimen/data_reduction_promo_normal_text_size" />
@@ skipping 39 matching lines @@
             android:layout_height="56dp"
             android:layout_width="56dp"
             android:layout_alignParentEnd="true"
             android:layout_alignParentTop="true"
             android:background="?android:attr/selectableItemBackground"
             android:contentDescription="@string/close"
             android:src="@drawable/btn_close" />
             
     </RelativeLayout>
 </org.chromium.chrome.browser.preferences.datareduction.DataReductionPromoView>