[Printing] Apply printing policy after capabilities are available.

'printers-added' event adds destinations without capabilities.
Capabilities and policies are pulled by getPrinterCapabilities() native
call but only capabilities are applied.
This happens most often in managed guest session where there isn't last
selected printer most of the time (for which it works a bit
differently).

Bug: 998103
Change-Id: Ibcb0965a01ff06bbd503edcc57a54b142df04903
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1772163Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: Vladislav Kuzkokov <vkuzkokov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692062}

chrome/browser/resources/print_preview/data/destination_store.js

@@ -1180,6 +1180,9 @@ cr.define('print_preview', function() {
                 assert(settingsInfo.printer)));
       }
       if (dest) {
+        if (settingsInfo.printer && settingsInfo.printer.policies) {
+          dest.policies = settingsInfo.printer.policies;
+        }
         if ((origin === print_preview.DestinationOrigin.LOCAL ||
              origin === print_preview.DestinationOrigin.CROS) &&
             dest.capabilities) {

chrome/test/data/webui/print_preview/destination_store_test.js

@@ -429,8 +429,9 @@ cr.define('destination_store_test', function() {
             const localDestinationInfo = {deviceName: id1, printerName: name1};
             if (cr.isChromeOS) {
               localDestinationInfo.policies = {
-                allowedColorModes: 0x1,
-                defaultColorMode: 0x1
+                allowedColorModes:
+                    print_preview.ColorModeRestriction.MONOCHROME,
+                defaultColorMode: print_preview.ColorModeRestriction.MONOCHROME,
               };
             }
             nativeLayer.setLocalDestinationCapabilities({
@@ -455,10 +456,9 @@ cr.define('destination_store_test', function() {
             assertEquals(destination, destinationStore.selectedDestination);
             // Capabilities are updated.
             assertTrue(!!destination.capabilities);
-            // TODO (https://crbug.com/998103): Ensure that the destination
-            // policies are actually set.
             if (cr.isChromeOS) {
-              assertEquals(null, destination.policies);
+              // Policies are updated.
+              assertTrue(!!destination.policies);
             }
           });
     });