Clean VM thread shutdown:

runtime/vm/verified_memory_test.cc

Index: runtime/vm/verified_memory_test.cc
diff --git a/runtime/vm/verified_memory_test.cc b/runtime/vm/verified_memory_test.cc
index 6d972167f9462b599008cd493077c51f7d57f2ee..90c21ec7fa72a9a54d833e20cce3cd1c891b89b5 100644
--- a/runtime/vm/verified_memory_test.cc
+++ b/runtime/vm/verified_memory_test.cc
@@ -15,12 +15,20 @@ void Init() {
 }
 
 
+void Shutdown() {
+#if defined(DEBUG)
+  FLAG_verified_mem = false;
+#endif
+}
+
+
 UNIT_TEST_CASE(VerifiedMemoryReserve) {
   Init();
   const intptr_t kReservationSize = 64 * KB;
   VirtualMemory* vm = VerifiedMemory::Reserve(kReservationSize);
   EXPECT_EQ(kReservationSize, vm->size());
   delete vm;
+  Shutdown();
 }
 
 
@@ -31,6 +39,7 @@ UNIT_TEST_CASE(VerifiedMemoryCommit) {
   EXPECT_EQ(kReservationSize, vm->size());
   vm->Commit(false);
   delete vm;
+  Shutdown();
 }
 
 
@@ -53,6 +62,7 @@ UNIT_TEST_CASE(VerifiedMemoryBasic) {
   *unverified = 123;
   VerifiedMemory::Verify(reinterpret_cast<uword>(addr), 3 * sizeof(double));
   delete vm;
+  Shutdown();
 }
 
 
@@ -72,6 +82,7 @@ UNIT_TEST_CASE(VerifiedMemoryAccept) {
   VerifiedMemory::Accept(reinterpret_cast<uword>(addr), 2 * sizeof(double));
   VerifiedMemory::Verify(reinterpret_cast<uword>(addr), 3 * sizeof(double));
   delete vm;
+  Shutdown();
 }
 
 
@@ -86,6 +97,7 @@ UNIT_TEST_CASE(VerifyImplicit_Crash) {
   double* addr = reinterpret_cast<double*>(vm->address());
   addr[0] = 0.5;  // Forget to use Write.
   VerifiedMemory::Write(&addr[0], 1.5);
+  Shutdown();
 }
 
 
@@ -101,6 +113,7 @@ UNIT_TEST_CASE(VerifyExplicit_Crash) {
   addr[1] = 3.5;  // Forget to use Write.
   VerifiedMemory::Write(&addr[2], 2.5);
   VerifiedMemory::Verify(reinterpret_cast<uword>(addr), 3 * sizeof(double));
+  Shutdown();
 }
 
 }  // namespace dart