Reland of Change mojo_public_bindings_unittests to use chromium environment.

third_party/mojo/src/mojo/public/cpp/bindings/tests/validation_unittest.cc

Index: third_party/mojo/src/mojo/public/cpp/bindings/tests/validation_unittest.cc
diff --git a/third_party/mojo/src/mojo/public/cpp/bindings/tests/validation_unittest.cc b/third_party/mojo/src/mojo/public/cpp/bindings/tests/validation_unittest.cc
index 09ee930213af99f12d98dc97ae1da41ba9e82a74..fc536c2af5022a6fd33a455dac2a7f02e017eca0 100644
--- a/third_party/mojo/src/mojo/public/cpp/bindings/tests/validation_unittest.cc
+++ b/third_party/mojo/src/mojo/public/cpp/bindings/tests/validation_unittest.cc
@@ -8,6 +8,8 @@
 #include <string>
 #include <vector>
 
+#include "base/message_loop/message_loop.h"
+#include "mojo/message_pump/message_pump_mojo.h"
 #include "mojo/public/c/system/macros.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/cpp/bindings/interface_ptr.h"
@@ -18,10 +20,8 @@
 #include "mojo/public/cpp/bindings/lib/validation_errors.h"
 #include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/bindings/tests/validation_test_input_parser.h"
-#include "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/system/core.h"
 #include "mojo/public/cpp/test_support/test_support.h"
-#include "mojo/public/cpp/utility/run_loop.h"
 #include "mojo/public/interfaces/bindings/tests/validation_test_interfaces.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -185,17 +185,13 @@
   }
 };
 
-class ValidationTest : public testing::Test {
- public:
-  ~ValidationTest() override {}
-
- private:
-  Environment env_;
-};
+using ValidationTest = testing::Test;
 
 class ValidationIntegrationTest : public ValidationTest {
  public:
-  ValidationIntegrationTest() : test_message_receiver_(nullptr) {}
+  ValidationIntegrationTest()
+      : loop_(common::MessagePumpMojo::Create()),
+        test_message_receiver_(nullptr) {}
 
   ~ValidationIntegrationTest() override {}
 
@@ -243,7 +239,7 @@
 
   void PumpMessages() { loop_.RunUntilIdle(); }
 
-  RunLoop loop_;
+  base::MessageLoop loop_;
   TestMessageReceiver* test_message_receiver_;
   ScopedMessagePipeHandle testee_endpoint_;
 };