[wrapper-tracing] Fix write barrier test

The test was manually hooking up a wrapper in a non-supported way.
Switch to using the providing bindings methods.

This was flushed out when incremental marking started scanning roots
right after the test and encountered a broken leftover object.

Bug: chromium:757440
Change-Id: I0636c48a22d88f2d85ded1ebab2732d3ef6de077
Reviewed-on: https://chromium-review.googlesource.com/997795Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548581}

third_party/WebKit/Source/bindings/core/v8/ScriptWrappableMarkingVisitorTest.cpp

@@ -9,6 +9,7 @@
 #include "bindings/core/v8/V8GCController.h"
 #include "core/testing/DeathAwareScriptWrappable.h"
 #include "platform/bindings/TraceWrapperV8Reference.h"
+#include "platform/bindings/V8DOMWrapper.h"
 #include "platform/bindings/V8PerIsolateData.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -379,16 +380,16 @@ TEST(ScriptWrappableMarkingVisitor, WriteBarrierForScriptWrappable) {
   HeapObjectHeader::FromPayload(target)->MarkWrapperHeader();
 
   // Create a 'wrapper' object.
-  v8::Local<v8::ObjectTemplate> t = v8::ObjectTemplate::New(scope.GetIsolate());
-  t->SetInternalFieldCount(2);
-  v8::Local<v8::Object> obj =
-      t->NewInstance(scope.GetContext()).ToLocalChecked();
+  v8::Local<v8::Object> wrapper = V8DOMWrapper::CreateWrapper(
+      scope.GetIsolate(), scope.GetContext()->Global(),
+      target->GetWrapperTypeInfo());
 
   // Upon setting the wrapper we should have executed the write barrier.
   CHECK_EQ(0u, raw_visitor->NumberOfMarkedWrappers());
-  bool success =
-      target->SetWrapper(scope.GetIsolate(), target->GetWrapperTypeInfo(), obj);
-  CHECK(success);
+  v8::Local<v8::Object> final_wrapper =
+      V8DOMWrapper::AssociateObjectWithWrapper(
+          scope.GetIsolate(), target, target->GetWrapperTypeInfo(), wrapper);
+  CHECK(!final_wrapper.IsEmpty());
   CHECK_EQ(1u, raw_visitor->NumberOfMarkedWrappers());
 }
 

third_party/WebKit/Source/platform/bindings/V8DOMWrapper.h

@@ -51,7 +51,7 @@ class V8DOMWrapper {
   STATIC_ONLY(V8DOMWrapper);
 
  public:
-  static v8::Local<v8::Object> CreateWrapper(
+  PLATFORM_EXPORT static v8::Local<v8::Object> CreateWrapper(
       v8::Isolate*,
       v8::Local<v8::Object> creation_context,
       const WrapperTypeInfo*);
@@ -61,11 +61,11 @@ class V8DOMWrapper {
   // ScriptWrappable is not yet associated with any wrapper.  Returns the
   // wrapper already associated or |wrapper| if not yet associated.
   // The caller should always use the returned value rather than |wrapper|.
-  WARN_UNUSED_RESULT static v8::Local<v8::Object> AssociateObjectWithWrapper(
-      v8::Isolate*,
-      ScriptWrappable*,
-      const WrapperTypeInfo*,
-      v8::Local<v8::Object> wrapper);
+  PLATFORM_EXPORT WARN_UNUSED_RESULT static v8::Local<v8::Object>
+  AssociateObjectWithWrapper(v8::Isolate*,
+                             ScriptWrappable*,
+                             const WrapperTypeInfo*,
+                             v8::Local<v8::Object> wrapper);
   static void SetNativeInfo(v8::Isolate*,
                             v8::Local<v8::Object>,
                             const WrapperTypeInfo*,