Refactor Android printing code to make it more testable.

printing/android/java/src/org/chromium/printing/PrintManagerDelegate.java

Index: printing/android/java/src/org/chromium/printing/PrintManagerDelegate.java
diff --git a/printing/android/java/src/org/chromium/printing/PrintManagerDelegate.java b/printing/android/java/src/org/chromium/printing/PrintManagerDelegate.java
new file mode 100644
index 0000000000000000000000000000000000000000..6e2cb67e9af2535db49649130494e7772440db0a
--- /dev/null
+++ b/printing/android/java/src/org/chromium/printing/PrintManagerDelegate.java
@@ -0,0 +1,23 @@
+// Copyright 2013 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.printing;
+
+import android.print.PrintAttributes;
+import android.print.PrintDocumentAdapter;
+
+/**
+ * Defines an interface for the Android system printing service, for easier testing.
+ * We can't simply extend from {@link android.print.PrintManager}, since it's a final class.
+ */
+public interface PrintManagerDelegate {
+
+    /**
+     * Same as {@link android.print.PrintManager#print}, except this doesn't return a
+     * {@link android.print.PrintJob} since the clients don't need it.
+     */
+    void print(String printJobName,
+               PrintDocumentAdapter documentAdapter,
+               PrintAttributes attributes);
+}