Changing SpawnChild to return a struct.

base/android/java/src/org/chromium/base/ParcelableWrapper.java

Index: base/android/java/src/org/chromium/base/ParcelableWrapper.java
diff --git a/base/android/java/src/org/chromium/base/ParcelableWrapper.java b/base/android/java/src/org/chromium/base/ParcelableWrapper.java
new file mode 100644
index 0000000000000000000000000000000000000000..ce92a8d60326c724cedc867340b9c88400c1a40d
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/ParcelableWrapper.java
@@ -0,0 +1,59 @@
+// Copyright 2017 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.base;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * A Parcelable and its associated ID.
+ * Used on the ParcelableChannel to send Parcelable's over a Mojo channel.
+ */
+public class ParcelableWrapper implements Parcelable {
+    private int mId;
+    private Parcelable mParcelable;
+
+    public ParcelableWrapper(int id, Parcelable parcelable) {
+        mId = id;
+        mParcelable = parcelable;
+    }
+
+    ParcelableWrapper(Parcel in) {
+        mId = in.readInt();
+        mParcelable = in.readParcelable(getClass().getClassLoader());
+    }
+
+    public int getId() {
+        return mId;
+    }
+
+    public Parcelable getParcelable() {
+        return mParcelable;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeInt(mId);
+        dest.writeParcelable(mParcelable, 0);
+    }
+
+    public static final Parcelable.Creator<ParcelableWrapper> CREATOR =
+            new Parcelable.Creator<ParcelableWrapper>() {
+                @Override
+                public ParcelableWrapper createFromParcel(Parcel in) {
+                    return new ParcelableWrapper(in);
+                }
+
+                @Override
+                public ParcelableWrapper[] newArray(int size) {
+                    return new ParcelableWrapper[size];
+                }
+            };
+}