AOD: Hold WakeLocks 100ms beyond release

Ensures (hopefully) that the underlying systems
have finished pushing the frames by the time the WakeLock is
released.

Bug: 36506840
Test: none, it is a pain to test this. Code is simple enough though.
Change-Id: I7b2f145f92319d5436a167d90b4703260ee08de6
diff --git a/packages/SystemUI/src/com/android/systemui/doze/DozeFactory.java b/packages/SystemUI/src/com/android/systemui/doze/DozeFactory.java
index 4d8323b..3ae0305 100644
--- a/packages/SystemUI/src/com/android/systemui/doze/DozeFactory.java
+++ b/packages/SystemUI/src/com/android/systemui/doze/DozeFactory.java
@@ -27,6 +27,7 @@
 import com.android.systemui.SystemUIApplication;
 import com.android.systemui.plugins.doze.DozeProvider;
 import com.android.systemui.statusbar.phone.DozeParameters;
+import com.android.systemui.util.wakelock.DelayedWakeLock;
 import com.android.systemui.util.wakelock.WakeLock;
 
 public class DozeFactory {
@@ -47,7 +48,8 @@
         AmbientDisplayConfiguration config = new AmbientDisplayConfiguration(context);
         DozeParameters params = new DozeParameters(context);
         Handler handler = new Handler();
-        WakeLock wakeLock = WakeLock.createPartial(context, "Doze");
+        WakeLock wakeLock = new DelayedWakeLock(handler,
+                WakeLock.createPartial(context, "Doze"));
 
         DozeMachine machine = new DozeMachine(
                 DozeSuspendScreenStatePreventingAdapter.wrapIfNeeded(
diff --git a/packages/SystemUI/src/com/android/systemui/util/wakelock/DelayedWakeLock.java b/packages/SystemUI/src/com/android/systemui/util/wakelock/DelayedWakeLock.java
new file mode 100644
index 0000000..b835909
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/util/wakelock/DelayedWakeLock.java
@@ -0,0 +1,52 @@
+/*
+ * 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.systemui.util.wakelock;
+
+import android.os.Handler;
+
+/**
+ * A wake lock that has a built in delay when releasing to give the framebuffer time to update.
+ */
+public class DelayedWakeLock implements WakeLock {
+
+    private static final long RELEASE_DELAY_MS = 100;
+
+    private final Handler mHandler;
+    private final WakeLock mInner;
+    private final Runnable mRelease;
+
+    public DelayedWakeLock(Handler h, WakeLock inner) {
+        mHandler = h;
+        mInner = inner;
+        mRelease = mInner::release;
+    }
+
+    @Override
+    public void acquire() {
+        mInner.acquire();
+    }
+
+    @Override
+    public void release() {
+        mHandler.postDelayed(mRelease, RELEASE_DELAY_MS);
+    }
+
+    @Override
+    public Runnable wrap(Runnable r) {
+        return WakeLock.wrapImpl(this, r);
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/util/wakelock/WakeLock.java b/packages/SystemUI/src/com/android/systemui/util/wakelock/WakeLock.java
index eea3de3..23c51d2 100644
--- a/packages/SystemUI/src/com/android/systemui/util/wakelock/WakeLock.java
+++ b/packages/SystemUI/src/com/android/systemui/util/wakelock/WakeLock.java
@@ -35,6 +35,17 @@
                     .newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, tag);
     }
 
+    static Runnable wrapImpl(WakeLock w, Runnable r) {
+        w.acquire();
+        return () -> {
+            try {
+                r.run();
+            } finally {
+                w.release();
+            }
+        };
+    }
+
     static WakeLock wrap(final PowerManager.WakeLock inner) {
         return new WakeLock() {
             /** @see PowerManager.WakeLock#acquire() */
@@ -49,7 +60,7 @@
 
             /** @see PowerManager.WakeLock#wrap(Runnable) */
             public Runnable wrap(Runnable runnable) {
-                return inner.wrap(runnable);
+                return wrapImpl(this, runnable);
             }
         };
     }