Unify the way cctest initalizes the VM for each test case.

test/cctest/cctest.cc

Index: test/cctest/cctest.cc
diff --git a/test/cctest/cctest.cc b/test/cctest/cctest.cc
index f1737602eafdb1d942421bad66cd2e0c6e2616f6..deed91aa57b54e5f3ba5a54acc559daf6ed1e3c1 100644
--- a/test/cctest/cctest.cc
+++ b/test/cctest/cctest.cc
@@ -57,6 +57,24 @@ CcTest::CcTest(TestFunction* callback, const char* file, const char* name,
 }
 
 
+v8::Persistent<v8::Context> CcTest::context_;
+
+
+void CcTest::InitializeVM(CcTestExtensionFlags extensions) {
+  const char* extension_names[kMaxExtensions];
+  int extension_count = 0;
+#define CHECK_EXTENSION_FLAG(Name, Id) \
+  if (extensions.Contains(Name##_ID)) extension_names[extension_count++] = Id;
+  EXTENSION_LIST(CHECK_EXTENSION_FLAG)
+#undef CHECK_EXTENSION_FLAG
+  if (context_.IsEmpty()) {
+    v8::ExtensionConfiguration config(extension_count, extension_names);
+    context_ = v8::Context::New(&config);
+  }
+  context_->Enter();
+}
+
+
 static void PrintTestList(CcTest* current) {
   if (current == NULL) return;
   PrintTestList(current->prev());
@@ -71,6 +89,7 @@ static void PrintTestList(CcTest* current) {
 
 v8::Isolate* CcTest::default_isolate_;
 
+
 int main(int argc, char* argv[]) {
   v8::internal::FlagList::SetFlagsFromCommandLine(&argc, argv, true);
   CcTest::set_default_isolate(v8::Isolate::GetCurrent());