Add PPDProvider barebones implementation and associated cache skeleton.

chromeos/printing/printer_translator_unittest.cc

 // Copyright 2016 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 <utility>
 
 #include "base/memory/ptr_util.h"
 #include "base/test/values_test_util.h"
 #include "base/values.h"
 #include "chromeos/printing/printer_configuration.h"
@@ skipping 86 matching lines @@
 // Make sure we don't serialize empty fields.
 TEST(PrinterTranslatorTest, PrinterToPrefPpdReferenceLazy) {
   Printer printer("UNIQUE_ID");
   std::unique_ptr<base::DictionaryValue> actual = PrinterToPref(printer);
 
   EXPECT_FALSE(actual->HasKey("ppd_reference.user_supplied_ppd_url"));
   EXPECT_FALSE(actual->HasKey("ppd_reference.effective_manufacturer"));
   EXPECT_FALSE(actual->HasKey("ppd_reference.effective_model"));
 }
 
-// FIXME add a test that we don't set fields that are empty.
-
 TEST(PrinterTranslatorTest, PrefToPrinterRoundTrip) {
   base::DictionaryValue preference;
   preference.SetString("id", kGUID);
   preference.SetString("display_name", kName);
   preference.SetString("description", kDescription);
   preference.SetString("manufacturer", kMake);
   preference.SetString("model", kModel);
   preference.SetString("uri", kUri);
   preference.SetString("uuid", kUUID);
 
   preference.SetString("ppd_reference.user_supplied_ppd_url",
                        kUserSuppliedPpdUrl);
   preference.SetString("ppd_reference.effective_manufacturer",
                        kEffectiveManufacturer);
   preference.SetString("ppd_reference.effective_model", kEffectiveModel);
 
   std::unique_ptr<Printer> printer = PrefToPrinter(preference);
   std::unique_ptr<base::DictionaryValue> pref_copy = PrinterToPref(*printer);
 
   EXPECT_TRUE(preference.Equals(pref_copy.get()));
 }
 
 }  // namespace printing
 }  // namespace chromeos