Remove MessageLoop references in /cc

MessageLoop is going away soon.

This CL was uploaded by git cl split.

R=samans@chromium.org

Bug: 891670
Change-Id: I15740af265a11a121228c63c6cca39541fcc6ed5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1946228
Auto-Submit: Carlos Caballero <carlscab@google.com>
Reviewed-by: Saman Sami <samans@chromium.org>
Commit-Queue: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#720833}

cc/test/cc_test_suite.cc

@@ -5,7 +5,7 @@
 #include "cc/test/cc_test_suite.h"
 
 #include "base/command_line.h"
-#include "base/message_loop/message_loop.h"
+#include "base/test/task_environment.h"
 #include "base/threading/thread_id_name_manager.h"
 #include "cc/base/histograms.h"
 #include "components/viz/test/paths.h"
@@ -21,7 +21,8 @@ CCTestSuite::~CCTestSuite() = default;
 
 void CCTestSuite::Initialize() {
   base::TestSuite::Initialize();
-  message_loop_ = std::make_unique<base::MessageLoop>();
+  task_environment_ =
+      std::make_unique<base::test::SingleThreadTaskEnvironment>();
 
   gl::GLSurfaceTestSupport::InitializeOneOff();
 
@@ -35,7 +36,7 @@ void CCTestSuite::Initialize() {
 }
 
 void CCTestSuite::Shutdown() {
-  message_loop_ = nullptr;
+  task_environment_ = nullptr;
 
   base::TestSuite::Shutdown();
 }

cc/test/cc_test_suite.h

@@ -11,8 +11,10 @@
 #include "base/test/test_suite.h"
 
 namespace base {
-class MessageLoop;
+namespace test {
+class SingleThreadTaskEnvironment;
 }
+}  // namespace base
 
 namespace cc {
 
@@ -30,7 +32,7 @@ class CCTestSuite : public base::TestSuite {
   void Shutdown() override;
 
  private:
-  std::unique_ptr<base::MessageLoop> message_loop_;
+  std::unique_ptr<base::test::SingleThreadTaskEnvironment> task_environment_;
 
   base::TestDiscardableMemoryAllocator discardable_memory_allocator_;
 };