Use TaskScheduler instead of WorkerPool in extension_printer_handler.cc.

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

Index: chrome/browser/ui/webui/print_preview/printer_handler.cc
diff --git a/chrome/browser/ui/webui/print_preview/printer_handler.cc b/chrome/browser/ui/webui/print_preview/printer_handler.cc
index 9e6f3dac919e78858b707c7da163ef1da02d58f3..14dad1238b3110f7b67a95796ffc340386433d00 100644
--- a/chrome/browser/ui/webui/print_preview/printer_handler.cc
+++ b/chrome/browser/ui/webui/print_preview/printer_handler.cc
@@ -4,12 +4,11 @@
 
 #include "chrome/browser/ui/webui/print_preview/printer_handler.h"
 
-#include "base/threading/worker_pool.h"
 #include "chrome/browser/ui/webui/print_preview/extension_printer_handler.h"
 
 // static
 std::unique_ptr<PrinterHandler> PrinterHandler::CreateForExtensionPrinters(
     content::BrowserContext* browser_context) {
-  return std::unique_ptr<ExtensionPrinterHandler>(new ExtensionPrinterHandler(
-      browser_context, base::WorkerPool::GetTaskRunner(true)));
+  return std::unique_ptr<ExtensionPrinterHandler>(
+      new ExtensionPrinterHandler(browser_context));
 }