mojo: java core API: Allow interaction with native handles

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

Index: mojo/public/java/system/src/org/chromium/mojo/system/InvalidHandle.java
diff --git a/mojo/public/java/system/src/org/chromium/mojo/system/InvalidHandle.java b/mojo/public/java/system/src/org/chromium/mojo/system/InvalidHandle.java
index 19d31ae8cb77b4ca48e3ada63f21f837acb5fe4c..12f0457291d912e257d73f1ab1efc4f50fcc903a 100644
--- a/mojo/public/java/system/src/org/chromium/mojo/system/InvalidHandle.java
+++ b/mojo/public/java/system/src/org/chromium/mojo/system/InvalidHandle.java
@@ -68,7 +68,6 @@ public class InvalidHandle implements UntypedHandle, MessagePipeHandle, Consumer
         return this;
     }
 
-
     /**
      * @see Handle#toUntypedHandle()
      */
@@ -78,6 +77,14 @@ public class InvalidHandle implements UntypedHandle, MessagePipeHandle, Consumer
     }
 
     /**
+     * @see Handle#releaseNativeHandle()
+     */
+    @Override
+    public int releaseNativeHandle() {
+        return -1;
+    }
+
+    /**
      * @see UntypedHandle#toMessagePipeHandle()
      */
     @Override