[Android] Upstream scene layers

chrome/android/java/src/org/chromium/chrome/browser/compositor/scene_layer/SceneLayer.java

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/scene_layer/SceneLayer.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/scene_layer/SceneLayer.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/scene_layer/SceneLayer.java
new file mode 100644
index 0000000000000000000000000000000000000000..84d8902c05a605bd9a9908e71c9868ea13b6c040
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/scene_layer/SceneLayer.java
@@ -0,0 +1,57 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.compositor.scene_layer;
+
+import org.chromium.base.CalledByNative;
+import org.chromium.base.JNINamespace;
+
+/**
+ * Java representation of a scene layer.
+ */
+@JNINamespace("chrome::android")
+public class SceneLayer {
+    private long mNativePtr;
+
+    /**
+     * Builds an instance of a {@link SceneLayer}.
+     */
+    public SceneLayer() {
+        initializeNative();
+    }
+
+    /**
+     * Initializes the native component of a {@link SceneLayer}.  Must be
+     * overridden to have a custom native component.
+     */
+    protected void initializeNative() {
+        if (mNativePtr == 0) {
+            mNativePtr = nativeInit();
+        }
+        assert mNativePtr != 0;
+    }
+
+    /**
+     * Destroys this object and the corresponding native component.
+     */
+    public void destroy() {
+        assert mNativePtr != 0;
+        nativeDestroy(mNativePtr);
+        assert mNativePtr == 0;
+    }
+
+    @CalledByNative
+    private void setNativePtr(long nativeSceneLayerPtr) {
+        assert mNativePtr == 0 || nativeSceneLayerPtr == 0;
+        mNativePtr = nativeSceneLayerPtr;
+    }
+
+    @CalledByNative
+    private long getNativePtr() {
+        return mNativePtr;
+    }
+
+    private native long nativeInit();
+    private native void nativeDestroy(long nativeSceneLayer);
+}