Free Isolate in ValueSerializerUnittest

BUG=v8:6316
R=jbroman@chromium.org,yangguo@chromium.org

Change-Id: Icfc33e3e51cdbfad246a971a5a2737a8fdfba058
Reviewed-on: https://chromium-review.googlesource.com/488941
Commit-Queue: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44963}

test/unittests/value-serializer-unittest.cc

@@ -1866,6 +1866,7 @@ TEST_F(ValueSerializerTest, DecodeArrayBufferOOM) {
   Isolate::CreateParams params;
   params.array_buffer_allocator = &allocator;
   Isolate* isolate = Isolate::New(params);
+  {
     Isolate::Scope isolate_scope(isolate);
     HandleScope handle_scope(isolate);
     Local<Context> context = Context::New(isolate);
@@ -1881,6 +1882,8 @@ TEST_F(ValueSerializerTest, DecodeArrayBufferOOM) {
     ASSERT_FALSE(try_catch.HasCaught());
     EXPECT_TRUE(deserializer.ReadValue(context).IsEmpty());
     EXPECT_TRUE(try_catch.HasCaught());
+  }
+  isolate->Dispose();
 }
 
 // Includes an ArrayBuffer wrapper marked for transfer from the serialization

tools/memory/lsan/suppressions.txt

@@ -14,6 +14,3 @@ leak:v8::internal::compiler::JumpThreading::ApplyForwarding
 # mjsunit
 leak:v8::internal::FuncNameInferrer::FuncNameInferrer
 leak:v8::internal::JSArrayBuffer::SetupAllocatingData
-
-# unittests
-leak:v8::internal::Isolate::FindOrAllocatePerThreadDataForThisThread