DialogSurfaceManager implementation.

media/base/android/java/src/org/chromium/media/AndroidOverlayProviderProxy.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 IAndroidOverlayProvider, to provide JNI bindings for arbitrary
+ * implementations of IAndroidOverlayProvider.  In practice, there is one: the
+ * IBinder stub we get from the browser.  However, if one creates a local
+ * provider such as in the GPU process, then this will work too.
+ *
+ * When one gets an IAndroidOverlayProvider, whether remote from the browser or
+ * local (if supported), it can be used by native classes by wrapping it in a
+ * AndroidOverlayProviderWrapper instance.
+ *
+ * Note that all of that is wrapped in the C++ bindings for this class, so see
+ * the docs in android_overlay_provider.h if you'd like to use this in C++.
+ * There's no need to use it in Java.
+ */
+@JNINamespace("media")
+class AndroidOverlayProviderProxy {
+    private final IAndroidOverlayProvider mProvider;
+
+    private AndroidOverlayProviderProxy(IAndroidOverlayProvider provider) {
+        mProvider = provider;
+    }
+
+    @CalledByNative
+    private static AndroidOverlayProviderProxy wrap(IBinder provider) {
+        return new AndroidOverlayProviderProxy(IAndroidOverlayProvider.Stub.asInterface(provider));
+    }
+
+    @CalledByNative
+    public IAndroidOverlay createOverlay(int rendererPid, int renderFrameId,
+            IAndroidOverlayCallback callback, int x, int y, int width, int height)
+            throws RemoteException {

[boliu, 2017/02/08 00:01:59]

any exception thrown by @CalledByNative methods will lead to an immediate native
crash

in this case, null is a valid return value rather than a failure case, so need
to catch that exception here and return null instead

+        return mProvider.createOverlay(rendererPid, renderFrameId, callback, x, y, width, height);
+    }
+}