Ensure tests have an active task runner

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/run_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/local_discovery/pwg_raster_converter.h"
 #include "chrome/browser/ui/webui/print_preview/extension_printer_handler.h"
 #include "chrome/test/base/testing_profile.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "extensions/browser/api/printer_provider/printer_provider_api.h"
 #include "extensions/browser/api/printer_provider/printer_provider_api_factory.h"
 #include "extensions/browser/api/printer_provider/printer_provider_print_job.h"
 #include "printing/pdf_render_settings.h"
 #include "printing/pwg_raster_settings.h"
 #include "printing/units.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/geometry/size.h"
 
 using extensions::PrinterProviderAPI;
@@ skipping 332 matching lines @@
   ~ExtensionPrinterHandlerTest() override = default;
 
   void SetUp() override {
     TestingProfile::Builder profile_builder;
     profile_builder.AddTestingFactory(
         extensions::PrinterProviderAPIFactory::GetInstance(),
         &BuildTestingPrinterProviderAPI);
     profile_ = profile_builder.Build();
 
     extension_printer_handler_.reset(new ExtensionPrinterHandler(
-        profile_.get(), message_loop_.task_runner()));
+        profile_.get(), base::MessageLoop::current()->task_runner()));
 
     pwg_raster_converter_ = new FakePWGRasterConverter();
     extension_printer_handler_->SetPwgRasterConverterForTesting(
         scoped_ptr<PWGRasterConverter>(pwg_raster_converter_));
   }
 
  protected:
   FakePrinterProviderAPI* GetPrinterProviderAPI() {
     return static_cast<FakePrinterProviderAPI*>(
         extensions::PrinterProviderAPIFactory::GetInstance()
             ->GetForBrowserContext(profile_.get()));
   }
 
   scoped_ptr<ExtensionPrinterHandler> extension_printer_handler_;
 
   FakePWGRasterConverter* pwg_raster_converter_;
 
  private:
-  base::MessageLoop message_loop_;
+  content::TestBrowserThreadBundle thread_bundle_;
 
   scoped_ptr<TestingProfile> profile_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionPrinterHandlerTest);
 };
 
 TEST_F(ExtensionPrinterHandlerTest, GetPrinters) {
   size_t call_count = 0;
   scoped_ptr<base::ListValue> printers;
   bool is_done = false;
@@ skipping 383 matching lines @@
   extension_printer_handler_->StartPrint(
       kPrinterId, kPWGRasterOnlyPrinterSimpleDescription, title,
       kEmptyPrintTicket, gfx::Size(100, 100), print_data,
       base::Bind(&RecordPrintResult, &call_count, &success, &status));
 
   EXPECT_EQ(1u, call_count);
 
   EXPECT_FALSE(success);
   EXPECT_EQ("INVALID_DATA", status);
 }