Add test for layer updates optimizations

Optimizations are following.

Change-Id: I120e1d0c08d8068fcac46515f37a4ae510e5f3a3
diff --git a/tests/HwAccelerationTest/AndroidManifest.xml b/tests/HwAccelerationTest/AndroidManifest.xml
index 4e229ec..4cb409d 100644
--- a/tests/HwAccelerationTest/AndroidManifest.xml
+++ b/tests/HwAccelerationTest/AndroidManifest.xml
@@ -42,6 +42,15 @@
         </activity>
 
         <activity
+                android:name="MultiLayersActivity"
+                android:label="_MultiLayers">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+        <activity
                 android:name="TJunctionActivity"
                 android:label="_T-Junction">
             <intent-filter>
diff --git a/tests/HwAccelerationTest/src/com/android/test/hwui/MultiLayersActivity.java b/tests/HwAccelerationTest/src/com/android/test/hwui/MultiLayersActivity.java
new file mode 100644
index 0000000..0127396
--- /dev/null
+++ b/tests/HwAccelerationTest/src/com/android/test/hwui/MultiLayersActivity.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2012 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.test.hwui;
+
+import android.app.Activity;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.os.Bundle;
+import android.view.View;
+import android.widget.LinearLayout;
+
+@SuppressWarnings("UnusedDeclaration")
+public class MultiLayersActivity extends Activity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        LinearLayout grid = new LinearLayout(this);
+        grid.setOrientation(LinearLayout.VERTICAL);
+
+        LinearLayout row1 = new LinearLayout(this);
+        row1.setOrientation(LinearLayout.HORIZONTAL);
+        grid.addView(row1, new LinearLayout.LayoutParams(
+                LinearLayout.LayoutParams.MATCH_PARENT, 0, 1.0f));
+
+        LinearLayout row2 = new LinearLayout(this);
+        row2.setOrientation(LinearLayout.HORIZONTAL);
+        grid.addView(row2, new LinearLayout.LayoutParams(
+                LinearLayout.LayoutParams.MATCH_PARENT, 0, 1.0f));
+
+        row1.addView(new LayerView(this, 0xffff0000), new LinearLayout.LayoutParams(
+                0, LinearLayout.LayoutParams.MATCH_PARENT, 1.0f));
+        row1.addView(new LayerView(this, 0xff00ff00), new LinearLayout.LayoutParams(
+                0, LinearLayout.LayoutParams.MATCH_PARENT, 1.0f));
+
+        row2.addView(new LayerView(this, 0xff0000ff), new LinearLayout.LayoutParams(
+                0, LinearLayout.LayoutParams.MATCH_PARENT, 1.0f));
+        row2.addView(new LayerView(this, 0xffffff00), new LinearLayout.LayoutParams(
+                0, LinearLayout.LayoutParams.MATCH_PARENT, 1.0f));
+
+        setContentView(grid);
+    }
+
+    private class LayerView extends View {
+        private final Paint mPaint;
+
+        public LayerView(Context context, int color) {
+            super(context);
+            mPaint = new Paint();
+            mPaint.setColor(color);
+            setLayerType(LAYER_TYPE_HARDWARE, null);
+        }
+
+        @Override
+        protected void onDraw(Canvas canvas) {
+            canvas.drawRect(0.0f, 0.0f, getWidth(), getHeight(), mPaint);
+            invalidate();
+        }
+    }
+}