Remove custom material styling for EditText in preferences

This is implemented in AppCompat now and our custom implementation
was causing bugs (e.g. the cursor was showing up white).

BUG=497608

Review URL: https://codereview.chromium.org/1169903003

Cr-Commit-Position: refs/heads/master@{#333762}

chrome/android/java/res/color/edit_text_tint.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. -->
-
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:state_enabled="true" android:state_focused="true"
-          android:color="@color/pref_accent_color"/>
-    <item android:state_enabled="true" android:state_activated="true"
-          android:color="@color/pref_accent_color"/>
-    <item android:state_enabled="false"
-          android:alpha="@dimen/disabled_alpha_material_dark"
-          android:color="@color/default_text_color" />
-    <item android:color="@color/input_underline_color" />
-</selector>
\ No newline at end of file

chrome/android/java/res/values-v21/styles.xml

@@ -8,8 +8,6 @@
     <style name="PreferencesTheme" parent="ThemeWithActionBar">
         <item name="android:textColorLink">@color/pref_accent_color</item>
         <item name="android:alertDialogTheme">@style/PreferencesDialogTheme</item>
-        <item name="android:editTextBackground">@drawable/abc_edit_text_material</item>
-        <item name="android:editTextStyle">@style/PreferenceEditTextStyle</item>
         <item name="android:spinnerItemStyle">@style/PreferenceSpinnerItem</item>
         <item name="floatLabelTextAppearance">@style/PreferenceFloatLabelTextAppearance</item>
         <item name="floatLabelPaddingLeft">@dimen/pref_autofill_field_horizontal_padding</item>
@@ -28,9 +26,6 @@
         <item name="android:textColor">@color/pref_accent_color</item>
         <item name="android:textSize">14sp</item>
     </style>
-    <style name="PreferenceEditTextStyle" parent="Widget.AppCompat.EditText">
-        <item name="android:backgroundTint">@color/edit_text_tint</item>
-    </style>
     <style name="PreferenceTitle">
         <item name="android:ellipsize">end</item>
         <item name="android:singleLine">true</item>