Inherit default text color from MainTheme.

chrome/android/java/res/layout/account_chooser_dialog_item.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. -->
 
 <LinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:minHeight="64dp"
@@ skipping 13 matching lines @@
         android:layout_margin="8dp"
         android:layout_marginStart="16dp"
         android:orientation="vertical">
         <TextView
             android:id="@+id/main_name"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:ellipsize="end"
             android:singleLine="true"
             android:fontFamily="sans-serif"
-            android:textColor="@color/default_text_color"
             android:textSize="@dimen/account_chooser_dialog_title_main_text_size"/>
         <TextView
             android:id="@+id/secondary_name"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:ellipsize="end"
             android:singleLine="true"
             android:fontFamily="sans-serif"
             android:textColor="@color/descriptive_text_color"
             android:textSize="@dimen/account_chooser_dialog_title_descriptive_text_size"/>
     </LinearLayout>
 </LinearLayout>