[Printing] Passing |scoped_refptr<...>| by value.

Updating code w.r.t. coding conventions:
https://chromium.googlesource.com/chromium/src/+/lkgr/styleguide/c++/c++.md#object-ownership-and-calling-conventions

Bug: 968109
Change-Id: Ib6aef90f69bfc10e7fe792502456427fce82a0e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1639217Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: Vladislav Kuzkokov <vkuzkokov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665525}

chrome/browser/printing/cloud_print/test/cloud_print_proxy_process_browsertest.cc

@@ -148,7 +148,7 @@ class MockServiceIPCServer : public ServiceIPCServer {
 
   MockServiceIPCServer(
       ServiceIPCServer::Client* client,
-      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
       base::WaitableEvent* shutdown_event)
       : ServiceIPCServer(client, io_task_runner, shutdown_event) {}
 

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

@@ -132,8 +132,7 @@ void PrivetPrinterHandler::OnPrivetPrintingError(
 }
 
 void PrivetPrinterHandler::StartLister(
-    const scoped_refptr<local_discovery::ServiceDiscoverySharedClient>&
-        client) {
+    scoped_refptr<local_discovery::ServiceDiscoverySharedClient> client) {
   DCHECK(!service_discovery_client_.get() ||
          service_discovery_client_.get() == client.get());
   service_discovery_client_ = client;

chrome/browser/ui/webui/print_preview/privet_printer_handler.h

@@ -66,8 +66,7 @@ class PrivetPrinterHandler
 
  private:
   void StartLister(
-      const scoped_refptr<local_discovery::ServiceDiscoverySharedClient>&
-          client);
+      scoped_refptr<local_discovery::ServiceDiscoverySharedClient> client);
   void StopLister();
   void CapabilitiesUpdateClient(
       std::unique_ptr<cloud_print::PrivetHTTPClient> http_client);

chrome/service/cloud_print/print_system_win.cc

@@ -438,7 +438,7 @@ class JobSpoolerWin : public PrintSystem::JobSpooler {
         const gfx::Rect& render_area,
         const gfx::Size& render_dpi,
         bool use_color,
-        const scoped_refptr<base::SingleThreadTaskRunner>& client_task_runner) {
+        scoped_refptr<base::SingleThreadTaskRunner> client_task_runner) {
       DCHECK(CurrentlyOnServiceIOThread());
       auto utility_host = std::make_unique<ServiceUtilityProcessHost>(
           this, client_task_runner.get());

components/printing/test/print_mock_render_thread.cc

@@ -41,7 +41,7 @@ PrintMockRenderThread::GetIOTaskRunner() {
 }
 
 void PrintMockRenderThread::set_io_task_runner(
-    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner) {
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
   io_task_runner_ = task_runner;
 }
 

components/printing/test/print_mock_render_thread.h

@@ -43,7 +43,7 @@ class PrintMockRenderThread : public content::MockRenderThread {
   // The following functions are called by the test itself.
 
   void set_io_task_runner(
-      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
 
 #if BUILDFLAG(ENABLE_PRINTING)
   // Returns the pseudo-printer instance.