Printing: Fix parameter type for local printer observer

Loosen the parameter restrictions for addListenerCallback() so the
DestinationStore can properly only expect LocalDestinationInfo for the
'local-printers-updated' event.

The 'local-printers-updated' event fired from PrintPreviewHandler
should only ever send LocalDestinationInfo.

Bug: b:300136694
Change-Id: Ic52a75572582d7970bfc9043d70138ec4dd35265
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4955615
Commit-Queue: Gavin Williams <gavinwill@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1213072}

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

@@ -234,11 +234,7 @@ export class DestinationStore extends EventTarget {
    */
   constructor(
       addListenerCallback:
-          (eventName: string,
-           listener:
-               (t: PrinterType,
-                p: LocalDestinationInfo[]|
-                ExtensionDestinationInfo[]) => void) => void) {
+          (eventName: string, listener: (p1: any, p2?: any) => void) => void) {
     super();
 
     this.destinationSearchStatus_ = new Map([
@@ -262,9 +258,8 @@ export class DestinationStore extends EventTarget {
     if (loadTimeData.getBoolean('isLocalPrinterObservingEnabled')) {
       addListenerCallback(
           'local-printers-updated',
-          (type: PrinterType,
-           printers: LocalDestinationInfo[]|ExtensionDestinationInfo[]) =>
-              this.onLocalPrintersUpdated_(type, printers));
+          (printers: LocalDestinationInfo[]) =>
+              this.onLocalPrintersUpdated_(printers));
     }
     // </if>
   }
@@ -974,24 +969,21 @@ export class DestinationStore extends EventTarget {
 
     this.nativeLayerCros_.observeLocalPrinters().then(
         (printers: LocalDestinationInfo[]) =>
-            this.onLocalPrintersUpdated_(PrinterType.LOCAL_PRINTER, printers));
+            this.onLocalPrintersUpdated_(printers));
   }
 
   /**
    * Inserts any new printers retrieved from the 'local-printers-updated' event.
    * @param printerType The type of printer(s) added.
    * @param printers Information about the printers that have been retrieved.
    */
-  private onLocalPrintersUpdated_(
-      printerType: PrinterType,
-      printers: LocalDestinationInfo[]|ExtensionDestinationInfo[]) {
+  private onLocalPrintersUpdated_(printers: LocalDestinationInfo[]) {
     if (!printers) {
       return;
     }
 
     this.insertDestinations_(printers.map(
-        (printer: LocalDestinationInfo|ExtensionDestinationInfo) =>
-            parseDestination(printerType, printer)));
+        printer => parseDestination(PrinterType.LOCAL_PRINTER, printer)));
   }
   // </if>
 }

chrome/browser/ui/webui/print_preview/print_preview_handler_chromeos.cc

@@ -420,7 +420,6 @@ void PrintPreviewHandlerChromeOS::OnHandleObserveLocalPrinters(
 void PrintPreviewHandlerChromeOS::OnLocalPrintersUpdated(
     std::vector<crosapi::mojom::LocalDestinationInfoPtr> printers) {
   FireWebUIListener("local-printers-updated",
-                    base::Value(static_cast<int>(mojom::PrinterType::kLocal)),
                     ConvertPrintersToValues(printers));
 }
 

chrome/browser/ui/webui/print_preview/print_preview_handler_chromeos_unittest.cc

@@ -496,9 +496,7 @@ TEST_F(PrintPreviewHandlerChromeOSTest, FireLocalPrintersUpdated) {
 
   const content::TestWebUI::CallData& data = *web_ui()->call_data().back();
   AssertWebUIEventFired(data, "local-printers-updated");
-  EXPECT_EQ(static_cast<int>(mojom::PrinterType::kLocal),
-            data.arg2()->GetInt());
-  EXPECT_EQ(printers.size(), data.arg3()->GetList().size());
+  EXPECT_EQ(printers.size(), data.arg2()->GetList().size());
 }
 
 }  // namespace printing

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

@@ -485,9 +485,7 @@ suite('DestinationStoreTest', function() {
 
       // Fire the event and expect the destination store to add the local
       // printers.
-      webUIListenerCallback(
-          'local-printers-updated', PrinterType.LOCAL_PRINTER,
-          [printer1, printer2]);
+      webUIListenerCallback('local-printers-updated', [printer1, printer2]);
       assertTrue(!!destinationStore.destinations().find(
           destination => destination.id === printer1.printerName));
       assertTrue(!!destinationStore.destinations().find(