Revert "Add synchronized lock for ringback playing start/stop request to avoid"

This reverts commit 7b6c9ba0b8b712d008009b323d5a25ebb4dc6ed1.

Reason for revert: seems to be the reason for test break b/276142299

Change-Id: I552292e7addc4f4b20241d6757b40c870fc359e1
diff --git a/src/com/android/server/telecom/RingbackPlayer.java b/src/com/android/server/telecom/RingbackPlayer.java
index e0c6136..a8af3ac 100644
--- a/src/com/android/server/telecom/RingbackPlayer.java
+++ b/src/com/android/server/telecom/RingbackPlayer.java
@@ -19,7 +19,6 @@
 import static com.android.server.telecom.LogUtils.Events.START_RINBACK;
 import static com.android.server.telecom.LogUtils.Events.STOP_RINGBACK;
 
-import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.Preconditions;
 import android.telecom.Log;
 
@@ -43,12 +42,8 @@
      */
     private InCallTonePlayer mTonePlayer;
 
-    private final Object mLock;
-
-    @VisibleForTesting
-    public RingbackPlayer(InCallTonePlayer.Factory playerFactory) {
+    RingbackPlayer(InCallTonePlayer.Factory playerFactory) {
         mPlayerFactory = playerFactory;
-        mLock = new Object();
     }
 
     /**
@@ -57,27 +52,25 @@
      * @param call The call for which to ringback.
      */
     public void startRingbackForCall(Call call) {
-        synchronized (mLock) {
-            Preconditions.checkState(call.getState() == CallState.DIALING);
+        Preconditions.checkState(call.getState() == CallState.DIALING);
 
-            if (mCall == call) {
-                Log.w(this, "Ignoring duplicate requests to ring for %s.", call);
-                return;
-            }
+        if (mCall == call) {
+            Log.w(this, "Ignoring duplicate requests to ring for %s.", call);
+            return;
+        }
 
-            if (mCall != null) {
-                // We only get here for the foreground call so, there's no reason why there should
-                // exist a current dialing call.
-                Log.wtf(this, "Ringback player thinks there are two foreground-dialing calls.");
-            }
+        if (mCall != null) {
+            // We only get here for the foreground call so, there's no reason why there should
+            // exist a current dialing call.
+            Log.wtf(this, "Ringback player thinks there are two foreground-dialing calls.");
+        }
 
-            mCall = call;
-            if (mTonePlayer == null) {
-                Log.i(this, "Playing the ringback tone for %s.", call);
-                Log.addEvent(call, START_RINBACK);
-                mTonePlayer = mPlayerFactory.createPlayer(InCallTonePlayer.TONE_RING_BACK);
-                mTonePlayer.startTone();
-            }
+        mCall = call;
+        if (mTonePlayer == null) {
+            Log.i(this, "Playing the ringback tone for %s.", call);
+            Log.addEvent(call, START_RINBACK);
+            mTonePlayer = mPlayerFactory.createPlayer(InCallTonePlayer.TONE_RING_BACK);
+            mTonePlayer.startTone();
         }
     }
 
@@ -87,27 +80,19 @@
      * @param call The call for which to stop ringback.
      */
     public void stopRingbackForCall(Call call) {
-        synchronized (mLock) {
-            if (mCall == call) {
-                // The foreground call is no longer dialing or is no longer the foreground call. In
-                // either case, stop the ringback tone.
-                mCall = null;
+        if (mCall == call) {
+            // The foreground call is no longer dialing or is no longer the foreground call. In
+            // either case, stop the ringback tone.
+            mCall = null;
 
-                if (mTonePlayer == null) {
-                    Log.w(this, "No player found to stop.");
-                } else {
-                    Log.i(this, "Stopping the ringback tone for %s.", call);
-                    Log.addEvent(call, STOP_RINGBACK);
-                    mTonePlayer.stopTone();
-                    mTonePlayer = null;
-                }
+            if (mTonePlayer == null) {
+                Log.w(this, "No player found to stop.");
+            } else {
+                Log.i(this, "Stopping the ringback tone for %s.", call);
+                Log.addEvent(call, STOP_RINGBACK);
+                mTonePlayer.stopTone();
+                mTonePlayer = null;
             }
         }
     }
-
-    public boolean isRingbackPlaying() {
-        synchronized (mLock) {
-            return mTonePlayer != null;
-        }
-    }
 }
\ No newline at end of file
diff --git a/tests/src/com/android/server/telecom/tests/RingbackPlayerTest.java b/tests/src/com/android/server/telecom/tests/RingbackPlayerTest.java
deleted file mode 100644
index f69d532..0000000
--- a/tests/src/com/android/server/telecom/tests/RingbackPlayerTest.java
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
- * Copyright (C) 2022 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.server.telecom.tests;
-
-import static org.junit.Assert.assertFalse;
-import static org.mockito.ArgumentMatchers.anyInt;
-import static org.mockito.Mockito.doAnswer;
-import static org.mockito.Mockito.doReturn;
-import static org.mockito.Mockito.when;
-
-import android.test.suitebuilder.annotation.SmallTest;
-
-import com.android.server.telecom.Call;
-import com.android.server.telecom.CallState;
-import com.android.server.telecom.InCallTonePlayer;
-import com.android.server.telecom.RingbackPlayer;
-
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.Mock;
-
-import java.util.concurrent.CountDownLatch;
-
-@RunWith(JUnit4.class)
-public class RingbackPlayerTest extends TelecomTestCase {
-    @Mock InCallTonePlayer.Factory mFactory;
-    @Mock Call mCall;
-    @Mock InCallTonePlayer mTonePlayer;
-
-    private RingbackPlayer mRingbackPlayer;
-
-    @Before
-    @Override
-    public void setUp() throws Exception {
-        super.setUp();
-        when(mFactory.createPlayer(anyInt())).thenReturn(mTonePlayer);
-        mRingbackPlayer = new RingbackPlayer(mFactory);
-    }
-
-    @SmallTest
-    @Test
-    public void testPlayerSync() {
-        // make sure InCallTonePlayer try to start playing the tone after RingbackPlayer receives
-        // stop tone request.
-        CountDownLatch latch = new CountDownLatch(1);
-        doReturn(CallState.DIALING).when(mCall).getState();
-        doAnswer(x -> {
-            new Thread(() -> {
-                try {
-                    latch.wait();
-                } catch (InterruptedException e) {
-                    // Ignore
-                }
-            }).start();
-            return true;
-        }).when(mTonePlayer).startTone();
-
-        mRingbackPlayer.startRingbackForCall(mCall);
-        mRingbackPlayer.stopRingbackForCall(mCall);
-        assertFalse(mRingbackPlayer.isRingbackPlaying());
-        latch.countDown();
-    }
-}