Remove requirement that mojo::Environment be instantiated.

mojo/public/cpp/bindings/tests/handle_passing_unittest.cc

Index: mojo/public/cpp/bindings/tests/handle_passing_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/handle_passing_unittest.cc b/mojo/public/cpp/bindings/tests/handle_passing_unittest.cc
index 3af49e424fe86f0a355e6c76898f874f37b9b309..ca11052c291a91e7fe4799f00cb3dd6a0000e766 100644
--- a/mojo/public/cpp/bindings/tests/handle_passing_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/handle_passing_unittest.cc
@@ -6,7 +6,6 @@
 
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
-#include "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/test_support/test_utils.h"
 #include "mojo/public/cpp/utility/run_loop.h"
 #include "mojo/public/interfaces/bindings/tests/sample_factory.mojom.h"
@@ -145,7 +144,6 @@ class HandlePassingTest : public testing::Test {
   void PumpMessages() { loop_.RunUntilIdle(); }
 
  private:
-  Environment env_;
   RunLoop loop_;
 };