Remove MessageLoop references in services/video_capture/test

MessageLoop is going away soon.

This CL was uploaded by git cl split.

R=chfremer@chromium.org

Bug: 891670
Change-Id: Ic9261b3931c4a01b8bde09d5d9c57d64ccaf8762
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1878193
Commit-Queue: Carlos Caballero <carlscab@google.com>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Auto-Submit: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#708995}

services/video_capture/test/mock_device_test.cc

@@ -5,8 +5,8 @@
 #include "services/video_capture/test/mock_device_test.h"
 
 #include "base/bind_helpers.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/test/task_environment.h"
 #include "media/capture/video/video_capture_system_impl.h"
 
 using testing::_;
@@ -20,7 +20,8 @@ MockDeviceTest::MockDeviceTest() = default;
 MockDeviceTest::~MockDeviceTest() = default;
 
 void MockDeviceTest::SetUp() {
-  message_loop_ = std::make_unique<base::MessageLoop>();
+  task_environment_ =
+      std::make_unique<base::test::SingleThreadTaskEnvironment>();
   auto mock_device_factory = std::make_unique<media::MockDeviceFactory>();
   // We keep a pointer to the MockDeviceFactory as a member so that we can
   // invoke its AddMockDevice(). Ownership of the MockDeviceFactory is moved

services/video_capture/test/mock_device_test.h

@@ -17,7 +17,9 @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
-class MessageLoop;
+namespace test {
+class SingleThreadTaskEnvironment;
+}
 }
 
 namespace video_capture {
@@ -46,7 +48,7 @@ class MockDeviceTest : public ::testing::Test {
   media::VideoCaptureParams requested_settings_;
 
  private:
-  std::unique_ptr<base::MessageLoop> message_loop_;
+  std::unique_ptr<base::test::SingleThreadTaskEnvironment> task_environment_;
 };
 
 }  // namespace video_capture