Implement safepointing of threads

runtime/vm/coverage_test.cc

Index: runtime/vm/coverage_test.cc
diff --git a/runtime/vm/coverage_test.cc b/runtime/vm/coverage_test.cc
index 1a2b0ebbab6196281d62e62327d06ac1d10b006f..f1afe992da58194c22b0defaa754172419e3de3f 100644
--- a/runtime/vm/coverage_test.cc
+++ b/runtime/vm/coverage_test.cc
@@ -9,6 +9,7 @@
 namespace dart {
 
 static RawObject* ExecuteScript(const char* script) {
+  TransitionVMToNative transition(Thread::Current());
   Dart_Handle h_lib = TestCase::LoadTestScript(script, NULL);
   EXPECT_VALID(h_lib);
   Library& lib = Library::Handle();
@@ -34,7 +35,7 @@ class FunctionCoverageFilter : public CoverageFilter {
 };
 
 
-TEST_CASE(Coverage_Empty) {
+VM_TEST_CASE(Coverage_Empty) {
   const char* kScript =
       "main() {\n"
       "}";
@@ -56,7 +57,7 @@ TEST_CASE(Coverage_Empty) {
 }
 
 
-TEST_CASE(Coverage_MainWithClass) {
+VM_TEST_CASE(Coverage_MainWithClass) {
   const char* kScript =
       "class Foo {\n"
       "  var x;\n"
@@ -100,7 +101,7 @@ TEST_CASE(Coverage_MainWithClass) {
 }
 
 
-TEST_CASE(Coverage_FilterFunction) {
+VM_TEST_CASE(Coverage_FilterFunction) {
   const char* kScript =
       "class Foo {\n"
       "  var x;\n"