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

test/cctest/test-disasm-ia32.cc

Index: test/cctest/test-disasm-ia32.cc
diff --git a/test/cctest/test-disasm-ia32.cc b/test/cctest/test-disasm-ia32.cc
index 8240a9546d22b2eff4ddd392004bbb541d81034b..ca81a5a4f5afd51dd45e2f3286126232171bb35a 100644
--- a/test/cctest/test-disasm-ia32.cc
+++ b/test/cctest/test-disasm-ia32.cc
@@ -38,14 +38,6 @@
 
 using namespace v8::internal;
 
-static v8::Persistent<v8::Context> env;
-
-static void InitializeVM() {
-  if (env.IsEmpty()) {
-    env = v8::Context::New();
-  }
-}
-
 
 #define __ assm.
 
@@ -55,8 +47,8 @@ static void DummyStaticFunction(Object* result) {
 
 
 TEST(DisasmIa320) {
-  InitializeVM();
-  Isolate* isolate = reinterpret_cast<Isolate*>(env->GetIsolate());
+  CcTest::InitializeVM();
+  Isolate* isolate = reinterpret_cast<Isolate*>(CcTest::isolate());
   HandleScope scope(isolate);
   v8::internal::byte buffer[2048];
   Assembler assm(isolate, buffer, sizeof buffer);