Process null capabilities as a capability fetch failure.

chrome/test/data/webui/print_preview_destination_search_test.js

 // 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.
 
 var ROOT_PATH = '../../../../';
 
 GEN_INCLUDE(
         [ROOT_PATH + 'chrome/test/data/webui/polymer_browser_test_base.js']);
 
 /**
@@ skipping 178 matching lines @@
       }
 
       var destId = "001122DEADBEEF";
 
       var resolver = mockSetupCall(destId, nativeLayer_);
       requestSetup(destId, destinationSearch_);
       resolver.reject(destId);
     });
 
     test('ReceiveSuccessfulSetup', function() {
-
       var destId = "00112233DEADBEEF";
 
       var waiter = waitForEvent(
           destinationStore_,
           print_preview.DestinationStore.EventType.DESTINATION_SELECT);
 
       var resolver = mockSetupCall(destId, nativeLayer_);
 
       requestSetup(destId, destinationSearch_);
       resolveSetup(resolver, destId, true, getCaps());
 
       // wait for event propogation to complete.
       return waiter.then(function() {
         // after setup succeeds, the destination should be selected.
         assertNotEquals(null, destinationStore_.selectedDestination);
         assertEquals(destId, destinationStore_.selectedDestination.id);
       });
     });
 
     test('ReceiveFailedSetup', function() {

[dpapad, 2017/05/02 00:07:41]

if (cr.isChromeOS) {
  test('ReceiveFailedSetup', function() {
     ...
  });
}

[skau, 2017/05/02 01:52:48]

Done.

+      if (!cr.isChromeOS) {
+        // The 'ResolutionFails' test covers this case for non-CrOS.

[dpapad, 2017/05/02 00:07:41]

ResolutionFails test also returns early for non-CrOS. Is this comment accurate?

[skau, 2017/05/02 01:52:48]

The comment is accurate.  The other test is disabled due to a bug because it
logs an error and causes the test to fail.

+        return;
+      }
+
       var destId = '00112233DEADBEEF';
 
       var resolver = mockSetupCall(destId, nativeLayer_);
       requestSetup(destId, destinationSearch_);
 
       // Force resolution to fail.
       resolveSetup(resolver, destId, false, null);
 
-      if (cr.isChromeOS) {
-        // Selection should not change on ChromeOS.
-        assertEquals(null, destinationStore_.selectedDestination);
-      } else {
-        // Other code expects selection to be present so it still occurs
-        // for non-CrOS.
-        assertEquals(destId, destinationStore_.selectedDestination.id);
-      }
+      // Selection should not change on ChromeOS.
+      assertEquals(null, destinationStore_.selectedDestination);
     });
   });
 
   mocha.run();
 });