diff --git a/services/tests/servicestests/src/com/android/server/wm/DragDropControllerTests.java b/services/tests/servicestests/src/com/android/server/wm/DragDropControllerTests.java
new file mode 100644
index 0000000..ce76a22
--- /dev/null
+++ b/services/tests/servicestests/src/com/android/server/wm/DragDropControllerTests.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2017 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.wm;
+
+import static android.view.WindowManager.LayoutParams.TYPE_BASE_APPLICATION;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import android.os.IBinder;
+import android.platform.test.annotations.Presubmit;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+import android.view.InputChannel;
+import android.view.Surface;
+import android.view.SurfaceSession;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+/**
+ * Tests for the {@link DragDropController} class.
+ *
+ * atest com.android.server.wm.DragDropControllerTests
+ */
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+@Presubmit
+public class DragDropControllerTests extends WindowTestsBase {
+    private static final int TIMEOUT_MS = 1000;
+    private DragDropController mTarget;
+    private WindowState mWindow;
+    private IBinder mToken;
+
+    @Before
+    public void setUp() throws Exception {
+        super.setUp();
+        assertNotNull(sWm.mDragDropController);
+        mTarget = sWm.mDragDropController;
+        mWindow = createWindow(null, TYPE_BASE_APPLICATION, "window");
+        synchronized (sWm.mWindowMap) {
+            // Because sWm is a static object, the previous operation may remain.
+            assertFalse(mTarget.dragDropActiveLocked());
+        }
+    }
+
+    @After
+    public void tearDown() {
+        if (mToken != null) {
+            mTarget.cancelDragAndDrop(mToken);
+        }
+    }
+
+    @Test
+    public void testPrepareDrag() throws Exception {
+        final Surface surface = new Surface();
+        mToken = mTarget.prepareDrag(
+                new SurfaceSession(), 0, 0, mWindow.mClient, 0, 100, 100, surface);
+        assertNotNull(mToken);
+    }
+
+    @Test
+    public void testPrepareDrag_ZeroSizeSurface() throws Exception {
+        final Surface surface = new Surface();
+        mToken = mTarget.prepareDrag(
+                new SurfaceSession(), 0, 0, mWindow.mClient, 0, 0, 0, surface);
+        assertNull(mToken);
+    }
+}