Remove references of MessageLoopForIO in /chrome/service

MessageLoopForIO will go away soon use ScopedTaskEnvironment instead.

ScopedTaskEnvironment will per default start a ThreadPool, which should
be fine in most of the cases. If you believe your test needs to make sure
that no ThreadPool runs let me know and I will update the patch.

BUG=891670
This CL was uploaded by git cl split.

R=rbpotter@chromium.org

Change-Id: I6488b766455b858343b2ca9b953027f001a077d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1733496
Auto-Submit: Carlos Caballero <carlscab@google.com>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683792}

chrome/service/cloud_print/cloud_print_url_fetcher_unittest.cc

@@ -6,10 +6,10 @@
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/values.h"
@@ -139,7 +139,8 @@ class CloudPrintURLFetcherTest : public testing::Test,
   // we assume that the current thread is the IO thread where the URLFetcher
   // dispatches its requests to.  When we wish to simulate being used from
   // a UI thread, we dispatch a worker thread to do so.
-  base::MessageLoopForIO io_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_{
+      base::test::ScopedTaskEnvironment::MainThreadType::IO};
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
   int max_retries_;
   Time start_time_;

chrome/service/cloud_print/printer_job_handler_unittest.cc

@@ -11,11 +11,11 @@
 #include "base/hash/md5.h"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/bind_test_util.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/common/cloud_print/cloud_print_constants.h"
 #include "chrome/service/cloud_print/cloud_print_service_helpers.h"
@@ -464,7 +464,8 @@ class PrinterJobHandlerTest : public ::testing::Test {
   void BeginTest(int timeout_seconds);
   void MakeJobFetchReturnNoJobs();
 
-  base::MessageLoopForIO loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_{
+      base::test::ScopedTaskEnvironment::MainThreadType::IO};
   base::OnceClosure active_run_loop_quit_closure_;
   TestURLFetcherCallback url_callback_;
   MockPrinterJobHandlerDelegate jobhandler_delegate_;
@@ -765,7 +766,7 @@ TEST_F(PrinterJobHandlerTest, DISABLED_ManyFailureTest) {
                            net::HTTP_INTERNAL_SERVER_ERROR,
                            net::URLRequestStatus::FAILED);
 
-  loop_.task_runner()->PostDelayedTask(
+  scoped_task_environment_.GetMainThreadTaskRunner()->PostDelayedTask(
       FROM_HERE,
       base::BindOnce(&net::FakeURLFetcherFactory::SetFakeResponse,
                      base::Unretained(&factory_), TicketURI(1),