mojo: java core API: Allow interaction with native handles

mojo/public/java/system/src/org/chromium/mojo/system/Core.java

Index: mojo/public/java/system/src/org/chromium/mojo/system/Core.java
diff --git a/mojo/public/java/system/src/org/chromium/mojo/system/Core.java b/mojo/public/java/system/src/org/chromium/mojo/system/Core.java
index f0ff6a0aba5bfbbc6aa4be45cf549814a0bd5415..d6c8e7da8d47eaaa9e11ec1408ad3e68f6e380a1 100644
--- a/mojo/public/java/system/src/org/chromium/mojo/system/Core.java
+++ b/mojo/public/java/system/src/org/chromium/mojo/system/Core.java
@@ -180,6 +180,14 @@ public interface Core {
             long numBytes);
 
     /**
+     * Acquires a handle from the native side. The handle will be owned by the returned object and
+     * must not be closed outside of it.
+     *
+     * @return a new {@link UntypedHandle} representing the native handle.
+     */
+    public UntypedHandle acquireNativeHandle(int handle);
+
+    /**
      * Returns a default implementation of {@link AsyncWaiter}.
      */
     public AsyncWaiter getDefaultAsyncWaiter();