Make PrinterProviderAPI a pure interface

extensions/browser/api/printer_provider/printer_provider_print_job.cc

Index: extensions/browser/api/printer_provider/printer_provider_print_job.cc
diff --git a/extensions/browser/api/printer_provider/printer_provider_print_job.cc b/extensions/browser/api/printer_provider/printer_provider_print_job.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3339daf08dc8aa68f6d52f464be2c50d6b2014d1
--- /dev/null
+++ b/extensions/browser/api/printer_provider/printer_provider_print_job.cc
@@ -0,0 +1,15 @@
+// Copyright 2015 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.
+
+#include "extensions/browser/api/printer_provider/printer_provider_print_job.h"
+
+namespace extensions {
+
+PrinterProviderPrintJob::PrinterProviderPrintJob() {
+}
+
+PrinterProviderPrintJob::~PrinterProviderPrintJob() {
+}
+
+}  // namespace extensions