Remove NetPrefObserver class and two prefs that do not do anything.

chrome/browser/android/preferences/pref_service_bridge.cc

 // 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.
 
 #include "chrome/browser/android/preferences/pref_service_bridge.h"
 
 #include <jni.h>
 #include <stddef.h>
 
 #include <memory>
@@ skipping 1000 matching lines @@
 
 static void SetNetworkPredictionEnabled(JNIEnv* env,
                                         const JavaParamRef<jobject>& obj,
                                         jboolean enabled) {
   GetPrefService()->SetInteger(
       prefs::kNetworkPredictionOptions,
       enabled ? chrome_browser_net::NETWORK_PREDICTION_WIFI_ONLY
               : chrome_browser_net::NETWORK_PREDICTION_NEVER);
 }
 
-static jboolean ObsoleteNetworkPredictionEnabledHasUserSetting(
-    JNIEnv* env,
-    const JavaParamRef<jobject>& obj) {
-  return GetPrefService()->GetUserPrefValue(
-      prefs::kNetworkPredictionEnabled) != NULL;
-}
-
 static jboolean ObsoleteNetworkPredictionOptionsHasUserSetting(
     JNIEnv* env,
     const JavaParamRef<jobject>& obj) {
   return GetPrefService()->GetUserPrefValue(
       prefs::kNetworkPredictionOptions) != NULL;
 }
 
-static jboolean ObsoleteGetNetworkPredictionEnabledUserPrefValue(
-    JNIEnv* env,
-    const JavaParamRef<jobject>& obj) {
-  const base::Value* network_prediction_enabled =
-      GetPrefService()->GetUserPrefValue(prefs::kNetworkPredictionEnabled);
-  DCHECK(network_prediction_enabled);
-  bool value = false;
-  DCHECK(network_prediction_enabled->GetAsBoolean(&value));
-  return value;
-}
-
 static void SetResolveNavigationErrorEnabled(JNIEnv* env,
                                              const JavaParamRef<jobject>& obj,
                                              jboolean enabled) {
   GetPrefService()->SetBoolean(prefs::kAlternateErrorPagesEnabled, enabled);
 }
 
 static jboolean GetFirstRunEulaAccepted(JNIEnv* env,
                                         const JavaParamRef<jobject>& obj) {
   return g_browser_process->local_state()->GetBoolean(prefs::kEulaAccepted);
 }
@@ skipping 138 matching lines @@
 
   return ConvertJavaStringToUTF8(android_permission);
 }
 
 static void SetSupervisedUserId(JNIEnv* env,
                                 const JavaParamRef<jobject>& obj,
                                 const JavaParamRef<jstring>& pref) {
   GetPrefService()->SetString(prefs::kSupervisedUserId,
                               ConvertJavaStringToUTF8(env, pref));
 }