diff --git a/Android.mk b/Android.mk
index 9630e34..ed85df0 100644
--- a/Android.mk
+++ b/Android.mk
@@ -288,7 +288,6 @@
 	core/java/com/android/internal/view/IInputMethodSession.aidl \
 	core/java/com/android/internal/view/IInputSessionCallback.aidl \
 	core/java/com/android/internal/widget/ILockSettings.aidl \
-	core/java/com/android/internal/widget/ILockSettingsObserver.aidl \
 	core/java/com/android/internal/widget/IRemoteViewsFactory.aidl \
 	core/java/com/android/internal/widget/IRemoteViewsAdapterConnection.aidl \
 	keystore/java/android/security/IKeyChainAliasCallback.aidl \
diff --git a/CleanSpec.mk b/CleanSpec.mk
index 28c2172..d660224 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -224,6 +224,7 @@
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/bin/inputflinger $(PRODUCT_OUT)/symbols/system/bin/inputflinger)
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/APPS/RsFountainFbo_intermediates)
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/framework-base_intermediates/src/telecomm/java/com/android/internal/telecomm)
+$(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/framework_intermediates/src/core/java/com/android/internal/widget/ILockSettingsObserver.java)
 
 # ******************************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST ABOVE THIS BANNER
diff --git a/core/java/com/android/internal/widget/ILockSettings.aidl b/core/java/com/android/internal/widget/ILockSettings.aidl
index c70841b..9501f92 100644
--- a/core/java/com/android/internal/widget/ILockSettings.aidl
+++ b/core/java/com/android/internal/widget/ILockSettings.aidl
@@ -16,8 +16,6 @@
 
 package com.android.internal.widget;
 
-import com.android.internal.widget.ILockSettingsObserver;
-
 /** {@hide} */
 interface ILockSettings {
     void setBoolean(in String key, in boolean value, in int userId);
@@ -34,6 +32,4 @@
     boolean havePattern(int userId);
     boolean havePassword(int userId);
     void removeUser(int userId);
-    void registerObserver(in ILockSettingsObserver observer);
-    void unregisterObserver(in ILockSettingsObserver observer);
 }
diff --git a/core/java/com/android/internal/widget/ILockSettingsObserver.aidl b/core/java/com/android/internal/widget/ILockSettingsObserver.aidl
deleted file mode 100644
index edf8f0e..0000000
--- a/core/java/com/android/internal/widget/ILockSettingsObserver.aidl
+++ /dev/null
@@ -1,31 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.android.internal.widget;
-
-/** {@hide} */
-oneway interface ILockSettingsObserver {
-    /**
-     * Called when a lock setting has changed.
-     *
-     * Note: Impementations of this should do as little work as possible, because this may be
-     * called synchronously while writing a setting.
-     *
-     * @param key the key of the setting that has changed or {@code null} if any may have changed.
-     * @param userId the user whose setting has changed.
-     */
-    void onLockSettingChanged(in String key, in int userId);
-}
diff --git a/core/java/com/android/internal/widget/LockPatternUtils.java b/core/java/com/android/internal/widget/LockPatternUtils.java
index a4b8380..3ccced5 100644
--- a/core/java/com/android/internal/widget/LockPatternUtils.java
+++ b/core/java/com/android/internal/widget/LockPatternUtils.java
@@ -65,13 +65,6 @@
     private static final boolean DEBUG = false;
 
     /**
-     * If true, LockPatternUtils will cache its values in-process. While this leads to faster reads,
-     * it can cause problems because writes to to the settings are no longer synchronous
-     * across all processes.
-     */
-    private static final boolean ENABLE_CLIENT_CACHE = false;
-
-    /**
      * The maximum number of incorrect attempts before the user is prevented
      * from trying again for {@link #FAILED_ATTEMPT_TIMEOUT_MS}.
      */
@@ -216,11 +209,7 @@
         if (mLockSettingsService == null) {
             ILockSettings service = ILockSettings.Stub.asInterface(
                     ServiceManager.getService("lock_settings"));
-            if (ENABLE_CLIENT_CACHE) {
-                mLockSettingsService = LockPatternUtilsCache.getInstance(service);
-            } else {
-                mLockSettingsService = service;
-            }
+            mLockSettingsService = service;
         }
         return mLockSettingsService;
     }
diff --git a/core/java/com/android/internal/widget/LockPatternUtilsCache.java b/core/java/com/android/internal/widget/LockPatternUtilsCache.java
deleted file mode 100644
index a9524ff..0000000
--- a/core/java/com/android/internal/widget/LockPatternUtilsCache.java
+++ /dev/null
@@ -1,262 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License
- */
-
-package com.android.internal.widget;
-
-import android.os.IBinder;
-import android.os.RemoteException;
-import android.os.UserHandle;
-import android.util.ArrayMap;
-import android.util.Log;
-
-/**
- * A decorator for {@link ILockSettings} that caches the key-value responses in memory.
- *
- * Specifically, the return values of {@link #getString(String, String, int)},
- * {@link #getLong(String, long, int)} and {@link #getBoolean(String, boolean, int)} are cached.
- */
-public class LockPatternUtilsCache implements ILockSettings {
-
-    private static final String TAG = "LockPatternUtilsCache";
-
-    public static final String HAS_LOCK_PATTERN_CACHE_KEY
-            = "LockPatternUtils.Cache.HasLockPatternCacheKey";
-    public static final String HAS_LOCK_PASSWORD_CACHE_KEY
-            = "LockPatternUtils.Cache.HasLockPasswordCacheKey";
-
-    private static LockPatternUtilsCache sInstance;
-
-    private final ILockSettings mService;
-
-    /** Only access when holding {@code mCache} lock. */
-    private final ArrayMap<CacheKey, Object> mCache = new ArrayMap<>();
-
-    /** Only access when holding {@link #mCache} lock. */
-    private final CacheKey mCacheKey = new CacheKey();
-
-
-    public static synchronized LockPatternUtilsCache getInstance(ILockSettings service) {
-        if (sInstance == null) {
-            sInstance = new LockPatternUtilsCache(service);
-        }
-        return sInstance;
-    }
-
-    // ILockSettings
-
-    public LockPatternUtilsCache(ILockSettings service) {
-        mService = service;
-        try {
-            service.registerObserver(mObserver);
-        } catch (RemoteException e) {
-            // Not safe to do caching without the observer. System process has probably died
-            // anyway, so crashing here is fine.
-            throw new RuntimeException(e);
-        }
-    }
-
-    public void setBoolean(String key, boolean value, int userId) throws RemoteException {
-        invalidateCache(key, userId);
-        mService.setBoolean(key, value, userId);
-        putCache(key, userId, value);
-    }
-
-    public void setLong(String key, long value, int userId) throws RemoteException {
-        invalidateCache(key, userId);
-        mService.setLong(key, value, userId);
-        putCache(key, userId, value);
-    }
-
-    public void setString(String key, String value, int userId) throws RemoteException {
-        invalidateCache(key, userId);
-        mService.setString(key, value, userId);
-        putCache(key, userId, value);
-    }
-
-    public long getLong(String key, long defaultValue, int userId) throws RemoteException {
-        Object value = peekCache(key, userId);
-        if (value instanceof Long) {
-            return (long) value;
-        }
-        long result = mService.getLong(key, defaultValue, userId);
-        putCache(key, userId, result);
-        return result;
-    }
-
-    public String getString(String key, String defaultValue, int userId) throws RemoteException {
-        Object value = peekCache(key, userId);
-        if (value instanceof String) {
-            return (String) value;
-        }
-        String result = mService.getString(key, defaultValue, userId);
-        putCache(key, userId, result);
-        return result;
-    }
-
-    public boolean getBoolean(String key, boolean defaultValue, int userId) throws RemoteException {
-        Object value = peekCache(key, userId);
-        if (value instanceof Boolean) {
-            return (boolean) value;
-        }
-        boolean result = mService.getBoolean(key, defaultValue, userId);
-        putCache(key, userId, result);
-        return result;
-    }
-
-    @Override
-    public void setLockPattern(String pattern, int userId) throws RemoteException {
-        invalidateCache(HAS_LOCK_PATTERN_CACHE_KEY, userId);
-        mService.setLockPattern(pattern, userId);
-        putCache(HAS_LOCK_PATTERN_CACHE_KEY, userId, pattern != null);
-    }
-
-    @Override
-    public boolean checkPattern(String pattern, int userId) throws RemoteException {
-        return mService.checkPattern(pattern, userId);
-    }
-
-    @Override
-    public void setLockPassword(String password, int userId) throws RemoteException {
-        invalidateCache(HAS_LOCK_PASSWORD_CACHE_KEY, userId);
-        mService.setLockPassword(password, userId);
-        putCache(HAS_LOCK_PASSWORD_CACHE_KEY, userId, password != null);
-    }
-
-    @Override
-    public boolean checkPassword(String password, int userId) throws RemoteException {
-        return mService.checkPassword(password, userId);
-    }
-
-    @Override
-    public boolean checkVoldPassword(int userId) throws RemoteException {
-        return mService.checkVoldPassword(userId);
-    }
-
-    @Override
-    public boolean havePattern(int userId) throws RemoteException {
-        Object value = peekCache(HAS_LOCK_PATTERN_CACHE_KEY, userId);
-        if (value instanceof Boolean) {
-            return (boolean) value;
-        }
-        boolean result = mService.havePattern(userId);
-        putCache(HAS_LOCK_PATTERN_CACHE_KEY, userId, result);
-        return result;
-    }
-
-    @Override
-    public boolean havePassword(int userId) throws RemoteException {
-        Object value = peekCache(HAS_LOCK_PASSWORD_CACHE_KEY, userId);
-        if (value instanceof Boolean) {
-            return (boolean) value;
-        }
-        boolean result = mService.havePassword(userId);
-        putCache(HAS_LOCK_PASSWORD_CACHE_KEY, userId, result);
-        return result;
-    }
-
-    @Override
-    public void removeUser(int userId) throws RemoteException {
-        mService.removeUser(userId);
-    }
-
-    @Override
-    public void registerObserver(ILockSettingsObserver observer) throws RemoteException {
-        mService.registerObserver(observer);
-    }
-
-    @Override
-    public void unregisterObserver(ILockSettingsObserver observer) throws RemoteException {
-        mService.unregisterObserver(observer);
-    }
-
-    @Override
-    public IBinder asBinder() {
-        return mService.asBinder();
-    }
-
-    // Caching
-
-    private Object peekCache(String key, int userId) {
-        if (!validateUserId(userId)) return null;
-        synchronized (mCache) {
-            // Safe to reuse mCacheKey, because it is not stored in the map.
-            return mCache.get(mCacheKey.set(key, userId));
-        }
-    }
-
-    private void putCache(String key, int userId, Object value) {
-        if (!validateUserId(userId)) return;
-        synchronized (mCache) {
-            // Create a new key, because this will be stored in the map.
-            mCache.put(new CacheKey().set(key, userId), value);
-        }
-    }
-
-    private void invalidateCache(String key, int userId) {
-        if (!validateUserId(userId)) return;
-        synchronized (mCache) {
-            if (key != null) {
-                // Safe to reuse mCacheKey, because it is not stored in the map.
-                mCache.remove(mCacheKey.set(key, userId));
-            } else {
-                mCache.clear();
-            }
-        }
-    }
-
-    private final ILockSettingsObserver mObserver = new ILockSettingsObserver.Stub() {
-        @Override
-        public void onLockSettingChanged(String key, int userId) throws RemoteException {
-            invalidateCache(key, userId);
-        }
-    };
-
-    private final boolean validateUserId(int userId) {
-        if (userId < UserHandle.USER_OWNER) {
-            Log.e(TAG, "User " + userId + " not supported: Must be a concrete user.");
-            return false;
-        }
-        return true;
-    }
-
-    private static final class CacheKey {
-        String key;
-        int userId;
-
-        public CacheKey set(String key, int userId) {
-            this.key = key;
-            this.userId = userId;
-            return this;
-        }
-
-        public CacheKey copy() {
-            return new CacheKey().set(key, userId);
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (!(obj instanceof CacheKey))
-                return false;
-            CacheKey o = (CacheKey) obj;
-            return userId == o.userId && key.equals(o.key);
-        }
-
-        @Override
-        public int hashCode() {
-            return key.hashCode() ^ userId;
-        }
-    }
-}
diff --git a/services/core/java/com/android/server/LockSettingsService.java b/services/core/java/com/android/server/LockSettingsService.java
index ae84846..77662cc 100644
--- a/services/core/java/com/android/server/LockSettingsService.java
+++ b/services/core/java/com/android/server/LockSettingsService.java
@@ -43,13 +43,10 @@
 import android.provider.Settings.SettingNotFoundException;
 import android.security.KeyStore;
 import android.text.TextUtils;
-import android.util.Log;
 import android.util.Slog;
 
 import com.android.internal.widget.ILockSettings;
-import com.android.internal.widget.ILockSettingsObserver;
 import com.android.internal.widget.LockPatternUtils;
-import com.android.internal.widget.LockPatternUtilsCache;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -65,9 +62,6 @@
 
     private static final String PERMISSION = ACCESS_KEYGUARD_SECURE_STORAGE;
 
-    private static final String SYSTEM_DEBUGGABLE = "ro.debuggable";
-
-
     private static final String TAG = "LockSettingsService";
 
     private final Context mContext;
@@ -77,8 +71,6 @@
     private LockPatternUtils mLockPatternUtils;
     private boolean mFirstCallToVold;
 
-    private final ArrayList<LockSettingsObserver> mObservers = new ArrayList<>();
-
     public LockSettingsService(Context context) {
         mContext = context;
         // Open the database
@@ -233,7 +225,6 @@
 
     private void setStringUnchecked(String key, int userId, String value) {
         mStorage.writeKeyValue(key, value, userId);
-        notifyObservers(key, userId);
     }
 
     @Override
@@ -261,52 +252,6 @@
     }
 
     @Override
-    public void registerObserver(ILockSettingsObserver remote) throws RemoteException {
-        synchronized (mObservers) {
-            for (int i = 0; i < mObservers.size(); i++) {
-                if (mObservers.get(i).remote.asBinder() == remote.asBinder()) {
-                    boolean isDebuggable = "1".equals(SystemProperties.get(SYSTEM_DEBUGGABLE, "0"));
-                    if (isDebuggable) {
-                        throw new IllegalStateException("Observer was already registered.");
-                    } else {
-                        Log.e(TAG, "Observer was already registered.");
-                        return;
-                    }
-                }
-            }
-            LockSettingsObserver o = new LockSettingsObserver();
-            o.remote = remote;
-            o.remote.asBinder().linkToDeath(o, 0);
-            mObservers.add(o);
-        }
-    }
-
-    @Override
-    public void unregisterObserver(ILockSettingsObserver remote) throws RemoteException {
-        synchronized (mObservers) {
-            for (int i = 0; i < mObservers.size(); i++) {
-                if (mObservers.get(i).remote.asBinder() == remote.asBinder()) {
-                    mObservers.remove(i);
-                    return;
-                }
-            }
-        }
-    }
-
-    public void notifyObservers(String key, int userId) {
-        synchronized (mObservers) {
-            for (int i = 0; i < mObservers.size(); i++) {
-                try {
-                    mObservers.get(i).remote.onLockSettingChanged(key, userId);
-                } catch (RemoteException e) {
-                    // The stack trace is not really helpful here.
-                    Log.e(TAG, "Failed to notify ILockSettingsObserver: " + e);
-                }
-            }
-        }
-    }
-
-    @Override
     public boolean havePassword(int userId) throws RemoteException {
         // Do we need a permissions check here?
 
@@ -354,7 +299,6 @@
         final byte[] hash = LockPatternUtils.patternToHash(
                 LockPatternUtils.stringToPattern(pattern));
         mStorage.writePatternHash(hash, userId);
-        notifyObservers(LockPatternUtilsCache.HAS_LOCK_PATTERN_CACHE_KEY, userId);
     }
 
     @Override
@@ -364,7 +308,6 @@
         maybeUpdateKeystore(password, userId);
 
         mStorage.writePasswordHash(mLockPatternUtils.passwordToHash(password, userId), userId);
-        notifyObservers(LockPatternUtilsCache.HAS_LOCK_PASSWORD_CACHE_KEY, userId);
     }
 
     @Override
@@ -452,7 +395,6 @@
         checkWritePermission(userId);
 
         mStorage.removeUser(userId);
-        notifyObservers(null /* key */, userId);
 
         final KeyStore ks = KeyStore.getInstance();
         final int userUid = UserHandle.getUid(userId, Process.SYSTEM_UID);
@@ -491,13 +433,4 @@
         }
         return null;
     }
-
-    private class LockSettingsObserver implements DeathRecipient {
-        ILockSettingsObserver remote;
-
-        @Override
-        public void binderDied() {
-            mObservers.remove(this);
-        }
-    }
 }