Use ScopedTaskEnvironment instead of MessageLoopForUI in ui tests.

ui/base/clipboard/clipboard_test_template.h

 // Copyright (c) 2012 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.
 //
 // Note: This header doesn't use REGISTER_TYPED_TEST_CASE_P like most
 // type-parameterized gtests. There are lot of test cases in here that are only
 // enabled on certain platforms. However, preprocessor directives in macro
 // arguments result in undefined behavior (and don't work on MSVC). Instead,
 // 'parameterized' tests should typedef TypesToTest (which is used to
 // instantiate the tests using the TYPED_TEST_CASE macro) and then #include this
 // header.
 // TODO(dcheng): This is really horrible. In general, all tests should run on
 // all platforms, to avoid this mess.
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
-#include "base/message_loop/message_loop.h"
 #include "base/pickle.h"
 #include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/scoped_task_environment.h"
 #include "build/build_config.h"
 #include "testing/gmock/include/gmock/gmock-matchers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkScalar.h"
 #include "third_party/skia/include/core/SkUnPreMultiply.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/clipboard/scoped_clipboard_writer.h"
@@ skipping 14 matching lines @@
 
 using testing::Contains;
 
 namespace ui {
 
 template <typename ClipboardTraits>
 class ClipboardTest : public PlatformTest {
  public:
 #if defined(USE_AURA)
   ClipboardTest()
-      : event_source_(ClipboardTraits::GetEventSource()),
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        event_source_(ClipboardTraits::GetEventSource()),
         clipboard_(ClipboardTraits::Create()) {}
 #else
-  ClipboardTest() : clipboard_(ClipboardTraits::Create()) {}
+  ClipboardTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        clipboard_(ClipboardTraits::Create()) {}
 #endif
 
   ~ClipboardTest() override { ClipboardTraits::Destroy(clipboard_); }
 
   bool IsMusTest() { return ClipboardTraits::IsMusTest(); }
 
  protected:
   Clipboard& clipboard() { return *clipboard_; }
 
   std::vector<base::string16> GetAvailableTypes(ClipboardType type) {
     bool contains_filenames;
     std::vector<base::string16> types;
     clipboard().ReadAvailableTypes(type, &types, &contains_filenames);
     return types;
   }
 
  private:
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 #if defined(USE_AURA)
   std::unique_ptr<PlatformEventSource> event_source_;
 #endif
   // ui::Clipboard has a protected destructor, so scoped_ptr doesn't work here.
   Clipboard* const clipboard_;
 };
 
 // Hack for tests that need to call static methods of ClipboardTest.
 struct NullClipboardTraits {
   static Clipboard* Create() { return nullptr; }
@@ skipping 583 matching lines @@
   ScopedClipboardWriter scw(CLIPBOARD_TYPE_COPY_PASTE);
   scw.WritePickledData(base::Pickle(), Clipboard::GetPlainTextFormatType());
 }
 
 TYPED_TEST(ClipboardTest, WriteImageEmptyParams) {
   ScopedClipboardWriter scw(CLIPBOARD_TYPE_COPY_PASTE);
   scw.WriteImage(SkBitmap());
 }
 
 }  // namespace ui