[Android] Simplify "network predictions" preference to a boolean value.

chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/NetworkPredictionPreference.java

-// 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.
-
-package org.chromium.chrome.browser.preferences.privacy;
-
-import android.content.Context;
-import android.preference.Preference;
-import android.preference.Preference.OnPreferenceChangeListener;
-import android.util.AttributeSet;
-
-import org.chromium.chrome.R;
-import org.chromium.chrome.browser.preferences.ChromeBaseListPreference;
-import org.chromium.chrome.browser.preferences.NetworkPredictionOptions;
-import org.chromium.chrome.browser.preferences.PrefServiceBridge;
-
-/**
- * Fragment to set and retrieve the prerender preference.
- */
-public class NetworkPredictionPreference extends ChromeBaseListPreference
-        implements OnPreferenceChangeListener {
-
-    private final Context mContext;
-
-    public NetworkPredictionPreference(Context context, AttributeSet attrs) {
-        super(context, attrs);
-        mContext = context;
-        String[] networkPredictionPrefs = context.getResources().getStringArray(
-                R.array.bandwidth_entries);
-        assert networkPredictionPrefs.length == NetworkPredictionOptions.choiceCount();
-        setOnPreferenceChangeListener(this);
-        setSummary(context.getString(
-                PrefServiceBridge.getInstance().getNetworkPredictionOptions().getDisplayTitle()));
-    }
-
-    @Override
-    public boolean onPreferenceChange(Preference preference, Object newValue) {
-        setSummary(mContext.getString(
-                NetworkPredictionOptions.stringToEnum((String) newValue).getDisplayTitle()));
-        return true;
-    }
-}