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=sammc@chromium.org

Change-Id: I4b3b1b6e59ca65ecdce281818234353955e5ff78
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1636352Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Sam McNally <sammc@chromium.org>
Auto-Submit: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#664706}

services/preferences/persistent_pref_store_impl_unittest.cc

@@ -7,8 +7,8 @@
 #include <utility>
 
 #include "base/macros.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 "components/prefs/in_memory_pref_store.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
@@ -73,7 +73,7 @@ class PersistentPrefStoreImplTest : public testing::Test {
   PersistentPrefStore* pref_store() { return pref_store_.get(); }
 
  private:
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   std::unique_ptr<PersistentPrefStoreImpl> impl_;
 

services/preferences/pref_store_consistency_unittest.cc

@@ -8,8 +8,8 @@
 #include "base/bind_helpers.h"
 #include "base/containers/circular_deque.h"
 #include "base/macros.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 "components/prefs/in_memory_pref_store.h"
 #include "components/prefs/pref_notifier_impl.h"
@@ -202,7 +202,7 @@ class PersistentPrefStoreConsistencyTest : public testing::Test {
  private:
   scoped_refptr<PersistentPrefStore> pref_store_;
   std::unique_ptr<PersistentPrefStoreImpl> pref_store_impl_;
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 };
 
 TEST_F(PersistentPrefStoreConsistencyTest, TwoPrefs) {

services/preferences/pref_store_impl_unittest.cc

@@ -7,8 +7,8 @@
 #include <utility>
 
 #include "base/macros.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 "components/prefs/value_map_pref_store.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
@@ -102,7 +102,7 @@ class PrefStoreImplTest : public testing::Test {
   PrefStore* pref_store() { return pref_store_.get(); }
 
  private:
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   std::unique_ptr<PrefStoreImpl> impl_;
 

services/preferences/public/cpp/tests/persistent_pref_store_client_unittest.cc

@@ -9,8 +9,8 @@
 
 #include "base/bind_helpers.h"
 #include "base/macros.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/sequenced_task_runner_handle.h"
 #include "base/values.h"
 #include "components/prefs/pref_notifier_impl.h"
@@ -102,7 +102,7 @@ class PersistentPrefStoreClientTest : public testing::Test,
   void ClearMutableValues() override {}
   void OnStoreDeletionFromDisk() override {}
 
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   std::unique_ptr<PrefService> pref_service_;
 

services/preferences/public/cpp/tests/pref_store_client_unittest.cc

@@ -5,8 +5,8 @@
 #include "services/preferences/public/cpp/pref_store_client.h"
 
 #include "base/macros.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 "services/preferences/public/mojom/preferences.mojom.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -66,7 +66,7 @@ class PrefStoreClientTest : public testing::Test {
   scoped_refptr<PrefStoreClient> store_;
 
   // Required by mojo binding code within PrefStoreClient.
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefStoreClientTest);
 };