DialogSurfaceManager implementation.

media/base/android/java/src/org/chromium/media/DialogSurfaceManagerWrapper.java

+// Copyright 2016 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.media;
+
+import android.os.IBinder;
+import android.os.RemoteException;
+
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+
+/**
+ * Wrapper for IDialogSurfaceManager, to provide JNI bindings for arbitrary
+ * implementations of IDialogSurfaceManager.  In practice, there is one: the
+ * IBinder stub we get from the browser.  However, if one creates a local
+ * manager such as in the GPU process, then this will work too.
+ *
+ * When one gets an IDialogSurfaceManager, whether remote from the browser or
+ * local (if supported), it can be used by native classes by wrapping it in a
+ * DialogSurfaceManagerWrapper instance.
+ *
+ * While it's not strictly needed, the wrapper implements IDialogSurfaceManager
+ * too.  It's helpful, since it makes changes to the interface into compile-
+ * time errors.
+ *
+ * Note that all of that is wrapped in the C++ bindings for this class, so see
+ * the docs in dialog_surface_manager.h if you'd like to use this in C++.
+ */
+@JNINamespace("media")
+class DialogSurfaceManagerWrapper implements IDialogSurfaceManager {

[boliu, 2017/01/04 01:48:44]

ditto about not needing to inherit from IDialogSurfaceManager here

[liberato (no reviews please), 2017/01/11 22:17:57]

will be removed along with the renaming in a separate PS.

+    private final IDialogSurfaceManager mManager;
+
+    private DialogSurfaceManagerWrapper(IDialogSurfaceManager manager) {
+        mManager = manager;
+    }
+
+    @CalledByNative
+    private static DialogSurfaceManagerWrapper wrap(IBinder manager) {
+        return new DialogSurfaceManagerWrapper(IDialogSurfaceManager.Stub.asInterface(manager));
+    }
+
+    @Override
+    @CalledByNative
+    public IDialogSurface createSurface(int rendererPid, int renderFrameId,
+            IDialogSurfaceCallback callback, int x, int y, int width, int height)
+            throws RemoteException {
+        return mManager.createSurface(rendererPid, renderFrameId, callback, x, y, width, height);
+    }
+
+    // We don't really implement a binderable interface, though I suppose that
+    // we could return mManager.asBinder().
+    @Override
+    public IBinder asBinder() {
+        return null;
+    }
+}