Backport some tests in /components/gcm_driver to SingleThreadTaskEnvironment

These tests were previously migrated from single-threaded MessageLoop to
a multi-threaded TaskEnvironment (then named ScopedTaskEnvironment) as
part of crbug.com/891670.

//base OWNERS decided in retrospect that it was better to keep a
single-threaded option for TaskEnvironment and introduced
SingleThreadTaskEnvironment. This CL retrofits that decision for
/components/gcm_driver.

This CL is a no-op if it passes CQ.

This CL was uploaded by git cl split.

R=fgorski@chromium.org

Bug: 891670
Change-Id: Ic03b7ee5179a0e97bff844b3df0913b574f25efb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1787138
Auto-Submit: Gabriel Charette <gab@chromium.org>
Reviewed-by: Jian Li <jianli@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#696098}

components/gcm_driver/account_tracker_unittest.cc

@@ -331,8 +331,8 @@ class AccountTrackerTest : public testing::Test {
 
  private:
   // net:: stuff needs IO message loop.
-  base::test::TaskEnvironment task_environment_{
-      base::test::TaskEnvironment::MainThreadType::IO};
+  base::test::SingleThreadTaskEnvironment task_environment_{
+      base::test::SingleThreadTaskEnvironment::MainThreadType::IO};
   network::TestURLLoaderFactory test_url_loader_factory_;
   signin::IdentityTestEnvironment identity_test_env_;
 

components/gcm_driver/crypto/gcm_encryption_provider_unittest.cc

@@ -189,7 +189,7 @@ class GCMEncryptionProviderTest : public ::testing::Test {
     encrypted_message_ = std::move(message);
   }
 
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   base::ScopedTempDir scoped_temp_dir_;
   base::HistogramTester histogram_tester_;
 

components/gcm_driver/crypto/gcm_key_store_unittest.cc

@@ -146,7 +146,7 @@ class GCMKeyStoreTest : public ::testing::Test {
   }
 
  private:
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   base::ScopedTempDir scoped_temp_dir_;
   base::HistogramTester histogram_tester_;
 

components/gcm_driver/gcm_account_tracker_unittest.cc

@@ -204,7 +204,7 @@ class GCMAccountTrackerTest : public testing::Test {
  private:
   CustomFakeGCMDriver driver_;
 
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   network::TestURLLoaderFactory test_url_loader_factory_;
   signin::IdentityTestEnvironment identity_test_env_;
 

components/gcm_driver/gcm_channel_status_request_unittest.cc

@@ -45,7 +45,7 @@ class GCMChannelStatusRequestTest : public testing::Test {
   network::TestURLLoaderFactory* test_url_loader_factory();
 
   std::unique_ptr<GCMChannelStatusRequest> request_;
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   network::TestURLLoaderFactory test_url_loader_factory_;
   scoped_refptr<network::SharedURLLoaderFactory> test_shared_loader_factory_;
   bool request_callback_invoked_;

components/gcm_driver/gcm_driver_desktop_unittest.cc

@@ -166,8 +166,8 @@ class GCMDriverTest : public testing::Test {
  private:
   base::ScopedTempDir temp_dir_;
   TestingPrefServiceSimple prefs_;
-  base::test::TaskEnvironment task_environment_{
-      base::test::TaskEnvironment::MainThreadType::UI};
+  base::test::SingleThreadTaskEnvironment task_environment_{
+      base::test::SingleThreadTaskEnvironment::MainThreadType::UI};
   base::Thread io_thread_;
   network::TestURLLoaderFactory test_url_loader_factory_;
 

components/gcm_driver/instance_id/instance_id_driver_unittest.cc

@@ -88,7 +88,7 @@ class InstanceIDDriverTest : public testing::Test {
   void GetTokenCompleted(const std::string& token, InstanceID::Result result);
   void DeleteTokenCompleted(InstanceID::Result result);
 
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   std::unique_ptr<FakeGCMDriverForInstanceID> gcm_driver_;
   std::unique_ptr<InstanceIDDriver> driver_;
 
@@ -109,7 +109,8 @@ class InstanceIDDriverTest : public testing::Test {
 };
 
 InstanceIDDriverTest::InstanceIDDriverTest()
-    : task_environment_(base::test::TaskEnvironment::MainThreadType::UI),
+    : task_environment_(
+          base::test::SingleThreadTaskEnvironment::MainThreadType::UI),
       result_(InstanceID::UNKNOWN_ERROR),
       async_operation_completed_(false) {}