Use ScopedTaskEnvironment instead of MessageLoop

MessageLoop will go away, eventually.

ScopedTaskEnvironment will per default start a ThreadPool, which should
be fine in most of the cases. If you belive 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=rsesek@chromium.org

Change-Id: I0a25ecf615af7e81acf65422c7f91870395bb68c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1636192Reviewed-by: Jay Civelli <jcivelli@chromium.org>
Commit-Queue: Carlos Caballero <carlscab@google.com>
Auto-Submit: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#665945}

services/data_decoder/image_decoder_impl_unittest.cc

@@ -7,8 +7,8 @@
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
-#include "base/message_loop/message_loop.h"
 #include "base/stl_util.h"
+#include "base/test/scoped_task_environment.h"
 #include "gin/array_buffer.h"
 #include "gin/public/isolate_holder.h"
 #include "services/data_decoder/image_decoder_impl.h"
@@ -108,7 +108,7 @@ class ImageDecoderImplTest : public testing::Test {
   ImageDecoderImpl* decoder() { return &decoder_; }
 
  private:
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   ImageDecoderImpl decoder_;
 };
 

services/data_decoder/public/cpp/json_sanitizer_unittest.cc

@@ -9,8 +9,8 @@
 #include "base/bind.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "services/data_decoder/public/cpp/safe_json_parser.h"
@@ -46,7 +46,7 @@ class JsonSanitizerTest : public ::testing::Test {
   void OnSuccess(const std::string& json);
   void OnError(const std::string& error);
 
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
 #if !defined(OS_ANDROID)
   TestingJsonParser::ScopedFactoryOverride factory_override_;

services/data_decoder/public/cpp/testing_json_parser_unittest.cc

@@ -8,8 +8,8 @@
 
 #include "base/bind.h"
 #include "base/callback.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/values.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -56,7 +56,7 @@ class TestingJsonParserTest : public testing::Test {
     EXPECT_FALSE(error.empty());
   }
 
-  base::MessageLoop message_loop;
+  base::test::ScopedTaskEnvironment scoped_task_environment;
   TestingJsonParser::ScopedFactoryOverride factory_override_;
   bool did_success_ = false;
   bool did_error_ = false;