List printers managed by extensions in print preview

extensions/browser/api/printer_provider_internal/printer_provider_internal_api.cc

Index: extensions/browser/api/printer_provider_internal/printer_provider_internal_api.cc
diff --git a/extensions/browser/api/printer_provider_internal/printer_provider_internal_api.cc b/extensions/browser/api/printer_provider_internal/printer_provider_internal_api.cc
index a5bd9eb6216e6fb655a594f2abf1c7adadabccef..e8879659d2a49b1fd64737c70868739221991123 100644
--- a/extensions/browser/api/printer_provider_internal/printer_provider_internal_api.cc
+++ b/extensions/browser/api/printer_provider_internal/printer_provider_internal_api.cc
@@ -47,7 +47,7 @@ void PrinterProviderInternalAPI::RemoveObserver(
 void PrinterProviderInternalAPI::NotifyGetPrintersResult(
     const Extension* extension,
     int request_id,
-    const base::ListValue& printers) {
+    const PrinterProviderInternalAPIObserver::PrinterInfoVector& printers) {
   FOR_EACH_OBSERVER(PrinterProviderInternalAPIObserver, observers_,
                     OnGetPrintersResult(extension, request_id, printers));
 }
@@ -132,17 +132,17 @@ PrinterProviderInternalReportPrintersFunction::Run() {
 
   base::ListValue printers;
   if (params->printers) {
-    for (size_t i = 0; i < params->printers->size(); ++i) {
-      scoped_ptr<base::DictionaryValue> printer(
-          params->printers->at(i)->ToValue());
-      printer->SetString("extensionId", extension()->id());
-      printers.Append(printer.release());
-    }
+    PrinterProviderInternalAPI::GetFactoryInstance()
+        ->Get(browser_context())
+        ->NotifyGetPrintersResult(extension(), params->request_id,
+                                  *params->printers);
+  } else {
+    PrinterProviderInternalAPI::GetFactoryInstance()
+        ->Get(browser_context())
+        ->NotifyGetPrintersResult(
+            extension(), params->request_id,
+            PrinterProviderInternalAPIObserver::PrinterInfoVector());
   }
-
-  PrinterProviderInternalAPI::GetFactoryInstance()
-      ->Get(browser_context())
-      ->NotifyGetPrintersResult(extension(), params->request_id, printers);
   return RespondNow(NoArguments());
 }