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/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);
+    }
+}