diff --git a/core/java/android/service/dreams/DreamActivity.java b/core/java/android/service/dreams/DreamActivity.java
index 0a29edc81f2fb..09d1bb9d2b123 100644
--- a/core/java/android/service/dreams/DreamActivity.java
+++ b/core/java/android/service/dreams/DreamActivity.java
@@ -21,6 +21,8 @@ import android.app.Activity;
 import android.os.Bundle;
 import android.view.WindowInsets;
 
+import com.android.internal.R;
+
 /**
  * The Activity used by the {@link DreamService} to draw screensaver content
  * on the screen. This activity runs in dream application's process, but is started by a
@@ -56,8 +58,20 @@ public class DreamActivity extends Activity {
         if (callback != null) {
             callback.onActivityCreated(this);
         }
+    }
 
+    @Override
+    public void onResume() {
+        super.onResume();
         // Hide all insets (nav bar, status bar, etc) when the dream is showing
         getWindow().getInsetsController().hide(WindowInsets.Type.systemBars());
+        overridePendingTransition(R.anim.dream_activity_open_enter,
+                                  R.anim.dream_activity_open_exit);
+    }
+
+    @Override
+    public void finishAndRemoveTask() {
+        super.finishAndRemoveTask();
+        overridePendingTransition(0, R.anim.dream_activity_close_exit);
     }
 }
diff --git a/core/java/android/service/dreams/DreamService.java b/core/java/android/service/dreams/DreamService.java
index 337027ef5bc99..4e9e3d49694e1 100644
--- a/core/java/android/service/dreams/DreamService.java
+++ b/core/java/android/service/dreams/DreamService.java
@@ -1052,7 +1052,6 @@ public class DreamService extends Service implements Window.Callback {
         mWindow.requestFeature(Window.FEATURE_NO_TITLE);
 
         WindowManager.LayoutParams lp = mWindow.getAttributes();
-        lp.windowAnimations = com.android.internal.R.style.Animation_Dream;
         lp.flags |= (WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
                     | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR
                     | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
diff --git a/core/res/res/anim/dream_activity_close_exit.xml b/core/res/res/anim/dream_activity_close_exit.xml
new file mode 100644
index 0000000000000..c4599dad31a06
--- /dev/null
+++ b/core/res/res/anim/dream_activity_close_exit.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/* Copyright 2020, 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.
+*/
+-->
+
+<alpha xmlns:android="http://schemas.android.com/apk/res/android"
+    android:fromAlpha="1.0"
+    android:toAlpha="0.0"
+    android:duration="100" />
+
diff --git a/core/res/res/anim/dream_activity_open_enter.xml b/core/res/res/anim/dream_activity_open_enter.xml
new file mode 100644
index 0000000000000..9e1c6e2ee0d72
--- /dev/null
+++ b/core/res/res/anim/dream_activity_open_enter.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/* Copyright 2020, 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.
+*/
+-->
+
+<!-- During this animation we keep the previous activity on the screen
+using a noop animation for it (dream_activity_open_exit). The duration of
+those two has to be the same. -->
+<alpha xmlns:android="http://schemas.android.com/apk/res/android"
+    android:fromAlpha="0.0"
+    android:toAlpha="1.0"
+    android:duration="1000" />
+
diff --git a/core/res/res/anim/dream_activity_open_exit.xml b/core/res/res/anim/dream_activity_open_exit.xml
new file mode 100644
index 0000000000000..740f52856b7f0
--- /dev/null
+++ b/core/res/res/anim/dream_activity_open_exit.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/* Copyright 2020, 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.
+*/
+-->
+
+<!-- A noop animation to keep the previous activity alive during the dream
+enter animation. The duration should match the duration of the
+dream_activity_open_enter animation. -->
+<alpha xmlns:android="http://schemas.android.com/apk/res/android"
+    android:fromAlpha="1.0"
+    android:toAlpha="1.0"
+    android:duration="1000" />
diff --git a/core/res/res/values/styles.xml b/core/res/res/values/styles.xml
index bcce1f05f0ddc..f920083f5cb30 100644
--- a/core/res/res/values/styles.xml
+++ b/core/res/res/values/styles.xml
@@ -248,12 +248,6 @@ please see styles_device_defaults.xml.
         <item name="windowExitAnimation">@anim/fast_fade_out</item>
     </style>
 
-    <!-- Window animations for screen savers. {@hide} -->
-    <style name="Animation.Dream">
-        <item name="windowEnterAnimation">@anim/slow_fade_in</item>
-        <item name="windowExitAnimation">@anim/fast_fade_out</item>
-    </style>
-
     <!-- Status Bar Styles -->
     <style name="TextAppearance.StatusBar">
         <item name="textAppearance">?attr/textAppearanceSmall</item>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index a82e7784b1671..bcfa1fe335122 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -1580,7 +1580,6 @@
   <java-symbol type="style" name="Animation.Tooltip" />
   <java-symbol type="style" name="Animation.TypingFilter" />
   <java-symbol type="style" name="Animation.TypingFilterRestore" />
-  <java-symbol type="style" name="Animation.Dream" />
   <java-symbol type="style" name="Theme.DeviceDefault.Dialog.Alert" />
   <java-symbol type="style" name="Theme.DeviceDefault.Light.Dialog.Alert" />
   <java-symbol type="style" name="Theme.Dialog.Alert" />
@@ -1825,6 +1824,9 @@
   <java-symbol type="anim" name="rotation_animation_jump_exit" />
   <java-symbol type="anim" name="rotation_animation_xfade_exit" />
   <java-symbol type="anim" name="rotation_animation_enter" />
+  <java-symbol type="anim" name="dream_activity_open_exit" />
+  <java-symbol type="anim" name="dream_activity_open_enter" />
+  <java-symbol type="anim" name="dream_activity_close_exit" />
   <java-symbol type="array" name="config_autoBrightnessButtonBacklightValues" />
   <java-symbol type="array" name="config_autoBrightnessKeyboardBacklightValues" />
   <java-symbol type="array" name="config_autoBrightnessLcdBacklightValues" />
diff --git a/core/res/res/values/themes.xml b/core/res/res/values/themes.xml
index 88f9fc2199e54..6e2995de0fe18 100644
--- a/core/res/res/values/themes.xml
+++ b/core/res/res/values/themes.xml
@@ -704,6 +704,7 @@ please see themes_device_defaults.xml.
     <style name="Theme.Dream">
         <item name="windowBackground">@color/black</item>
         <item name="windowDisablePreview">true</item>
+        <item name="windowActivityTransitions">true</item>
     </style>
 
     <!-- Default theme for dialog windows and activities (on API level 10 and lower),
diff --git a/services/core/java/com/android/server/wm/AppTransitionController.java b/services/core/java/com/android/server/wm/AppTransitionController.java
index 654ccc80f8a8c..67fe9685fd2aa 100644
--- a/services/core/java/com/android/server/wm/AppTransitionController.java
+++ b/services/core/java/com/android/server/wm/AppTransitionController.java
@@ -166,19 +166,13 @@ public class AppTransitionController {
         // done behind a dream window.
         final ArraySet<Integer> activityTypes = collectActivityTypes(mDisplayContent.mOpeningApps,
                 mDisplayContent.mClosingApps, mDisplayContent.mChangingContainers);
-        final boolean allowAnimations = mDisplayContent.getDisplayPolicy().allowAppAnimationsLw();
-        final ActivityRecord animLpActivity = allowAnimations
-                ? findAnimLayoutParamsToken(transit, activityTypes)
-                : null;
-        final ActivityRecord topOpeningApp = allowAnimations
-                ? getTopApp(mDisplayContent.mOpeningApps, false /* ignoreHidden */)
-                : null;
-        final ActivityRecord topClosingApp = allowAnimations
-                ? getTopApp(mDisplayContent.mClosingApps, false /* ignoreHidden */)
-                : null;
-        final ActivityRecord topChangingApp = allowAnimations
-                ? getTopApp(mDisplayContent.mChangingContainers, false /* ignoreHidden */)
-                : null;
+        final ActivityRecord animLpActivity = findAnimLayoutParamsToken(transit, activityTypes);
+        final ActivityRecord topOpeningApp =
+                getTopApp(mDisplayContent.mOpeningApps, false /* ignoreHidden */);
+        final ActivityRecord topClosingApp =
+                getTopApp(mDisplayContent.mClosingApps, false /* ignoreHidden */);
+        final ActivityRecord topChangingApp =
+                getTopApp(mDisplayContent.mChangingContainers, false /* ignoreHidden */);
         final WindowManager.LayoutParams animLp = getAnimLp(animLpActivity);
         overrideWithRemoteAnimationIfSet(animLpActivity, transit, activityTypes);
 
diff --git a/services/core/java/com/android/server/wm/DisplayPolicy.java b/services/core/java/com/android/server/wm/DisplayPolicy.java
index 541be0a8b580c..53b536cf712f1 100644
--- a/services/core/java/com/android/server/wm/DisplayPolicy.java
+++ b/services/core/java/com/android/server/wm/DisplayPolicy.java
@@ -3154,16 +3154,6 @@ public class DisplayPolicy {
         return 0;
     }
 
-    /**
-     * Return true if it is okay to perform animations for an app transition
-     * that is about to occur. You may return false for this if, for example,
-     * the dream window is currently displayed so the switch should happen
-     * immediately.
-     */
-    public boolean allowAppAnimationsLw() {
-        return !mShowingDream;
-    }
-
     private void requestTransientBars(WindowState swipeTarget) {
         if (!mService.mPolicy.isUserSetupComplete()) {
             // Swipe-up for navigation bar is disabled during setup