Use ScopedTaskEnvironment instead of MessageLoopForUI in components tests.

components/rappor/log_uploader_unittest.cc

 // Copyright 2014 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 "components/rappor/log_uploader.h"
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "net/url_request/test_url_fetcher_factory.h"
 #include "net/url_request/url_request_test_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace rappor {
 
 namespace {
 
 const char kTestServerURL[] = "http://a.com/";
@@ skipping 33 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestLogUploader);
 };
 
 }  // namespace
 
 class LogUploaderTest : public testing::Test {
  public:
   LogUploaderTest()
-      : request_context_(new net::TestURLRequestContextGetter(
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        request_context_(new net::TestURLRequestContextGetter(
             base::ThreadTaskRunnerHandle::Get())),
         factory_(NULL) {}
 
  protected:
   // Required for base::ThreadTaskRunnerHandle::Get().
-  base::MessageLoopForUI loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   scoped_refptr<net::TestURLRequestContextGetter> request_context_;
   net::FakeURLFetcherFactory factory_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LogUploaderTest);
 };
 
 TEST_F(LogUploaderTest, Success) {
   TestLogUploader uploader(request_context_.get());
 
@@ skipping 70 matching lines @@
   // Backoff until the maximum is reached.
   while (next > current) {
     current = next;
     next = TestLogUploader::BackOff(current);
   }
   // Maximum backoff should have been reached.
   EXPECT_EQ(next, current);
 }
 
 }  // namespace rappor