Remove unused Preference themes, styles, layouts

There are no longer any non-support library Alert Dialogs in
Preferences, so this theme can be removed from this activity (but is
still necessary on other activities).

The other preference-specific styles removed here were applicable only
to framework preferences and are no longer used now that all preferences
have been migrated to the support library.

Bug: 967022
Change-Id: Id367c240486b8f4bf6b892f859cd1aba5d16da73
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1711146Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Natalie Chouinard <chouinard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682350}

chrome/android/java/res/layout/preference_category.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. -->
-
-<!-- Emulates Android's preference_category_material.xml on pre-L devices.
-     Also used as the layout for IconPreferenceCategory. -->
-<LinearLayout
-    xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content"
-    android:gravity="center_vertical"
-    style="@style/PreferenceCategoryWithButtonStyle" >
-
-    <TextView
-        android:id="@android:id/title"
-        android:layout_width="0dp"
-        android:layout_weight="1"
-        android:layout_height="wrap_content"
-        android:textAppearance="@style/TextAppearance.PreferenceCategoryText" />
-
-    <!-- Users of this layout are responsible to set contentDescription. -->
-    <ImageView
-        android:id="@android:id/icon"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:minHeight="@dimen/min_touch_target_size"
-        android:minWidth="@dimen/min_touch_target_size"
-        android:scaleType="center"
-        android:background="?android:attr/selectableItemBackground"
-        tools:ignore="ContentDescription" />
-
-</LinearLayout>
\ No newline at end of file

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

@@ -152,7 +152,6 @@
         <!-- Theme attributes pre-v21 -->
         <item name="android:textAppearanceMedium">@style/TextAppearance.PreferenceMediumText</item>
         <item name="android:textAppearanceSmall">@style/TextAppearance.BlackBody</item>
-        <item name="android:preferenceCategoryStyle">@style/PreferenceCategory</item>
         <item name="android:windowContentOverlay">@null</item>
         <item name="preferenceTheme">@style/Theme.Chromium.PreferenceTheme</item>
     </style>
@@ -297,10 +296,10 @@
         <item name="buttonBarButtonStyle">@style/TextAppearance.DialogButtonCompat</item>
     </style>
 
-    <!-- TODO(chouinard): Using all caps for support library preference dialog buttons to match
-         existing non-compat style, however we should later reexamine whether this is still the
-         right choice since it looks like most of our other AlertDialogs use the default title case.
-         -->
+    <!-- TODO(crbug.com/971791): Using all caps for support library preference dialog buttons to
+         match existing non-compat style, however we should later reexamine whether this is still
+         the right choice since it looks like most of our other AlertDialogs use the default title
+         case. -->
     <style name="TextAppearance.DialogButtonCompat" parent="AlertDialogButtonStyle">
         <item name="android:textAllCaps">true</item>
     </style>
@@ -317,21 +316,6 @@
         <item name="android:textSize">18sp</item>
         <item name="android:textColor">?android:attr/textColorPrimary</item>
     </style>
-    <style name="PreferenceCategory">
-        <item name="android:layout">@layout/preference_category</item>
-        <item name="android:shouldDisableView">false</item>
-        <item name="android:selectable">false</item>
-    </style>
-    <style name="PreferenceCategoryWithButtonStyle">
-        <item name="android:paddingStart">8dp</item>
-        <item name="android:paddingEnd">4dp</item>
-        <item name="android:paddingTop">16dp</item>
-        <item name="android:layout_marginBottom">16dp</item>
-    </style>
-    <style name="TextAppearance.PreferenceCategoryText" parent="TextAppearance.RobotoMediumStyle">
-        <item name="android:textColor">@color/pref_accent_color</item>
-        <item name="android:textSize">12sp</item>
-    </style>
     <style name="PreferenceTitle">
         <item name="android:ellipsize">end</item>
         <item name="android:singleLine">true</item>

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

@@ -18,12 +18,6 @@
 
     <!-- Preferences -->
     <style name="Theme.Chromium.Preferences" parent="Base.Theme.Chromium.Preferences">
-        <item name="android:divider">@null</item>
-        <!-- Overriding alertDialogTheme pre-v21 with our custom AlertDialog theme causes bad visual
-             states on ListPreference because we don't use the support library ListPreference. -->
-        <item name="android:alertDialogTheme">@style/Theme.Chromium.AlertDialog</item>
-        <!-- TODO(crbug.com/967022): Clean up the unnecessary preference alert dialog styles once
-             all dialog preferences are migrated to the support library. -->
         <item name="alertDialogTheme">@style/Theme.Chromium.Preferences.AlertDialog</item>
         <item name="preferenceTheme">@style/Theme.Chromium.PreferenceTheme</item>
     </style>
@@ -52,14 +46,6 @@
         <item name="android:paddingStart">16dp</item>
     </style>
 
-    <style name="PreferenceCategoryWithButtonStyle">
-        <item name="android:paddingStart">?android:attr/listPreferredItemPaddingStart</item>
-        <item name="android:paddingEnd">4dp</item>
-    </style>
-    <style name="TextAppearance.PreferenceCategoryText" parent="TextAppearance.RobotoMediumStyle">
-        <item name="android:textColor">@color/pref_accent_color</item>
-        <item name="android:textSize">12sp</item>
-    </style>
     <style name="PreferenceTitle">
         <item name="android:ellipsize">end</item>
         <item name="android:singleLine">true</item>