Store ScriptWrappableVisitor in V8PerIsolateData

Store a reference of ScriptWrappableVisitor also in V8PerIsolateData so it can
be accessed from blink code easily (for example when oilpan will want to trace
ScriptWrappableVisitor's marking deque :)

LOG=no
BUG=468240

Review-Url: https://codereview.chromium.org/2033583007
Cr-Commit-Position: refs/heads/master@{#398003}

third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp

@@ -290,8 +290,9 @@ static void initializeV8Common(v8::Isolate* isolate)
     isolate->AddGCPrologueCallback(V8GCController::gcPrologue);
     isolate->AddGCEpilogueCallback(V8GCController::gcEpilogue);
     if (RuntimeEnabledFeatures::traceWrappablesEnabled()) {
-        ScriptWrappableVisitor* visitor = new ScriptWrappableVisitor(isolate);
-        isolate->SetEmbedderHeapTracer(visitor);
+        std::unique_ptr<ScriptWrappableVisitor> visitor(new ScriptWrappableVisitor(isolate));
+        isolate->SetEmbedderHeapTracer(visitor.get());
+        V8PerIsolateData::from(isolate)->setScriptWrappableVisitor(std::move(visitor));
     }
 
     v8::Debug::SetLiveEditEnabled(isolate, false);

third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.h

@@ -28,6 +28,7 @@
 
 #include "bindings/core/v8/ScopedPersistent.h"
 #include "bindings/core/v8/ScriptState.h"
+#include "bindings/core/v8/ScriptWrappableVisitor.h"
 #include "bindings/core/v8/V8HiddenValue.h"
 #include "bindings/core/v8/WrapperTypeInfo.h"
 #include "core/CoreExport.h"
@@ -146,6 +147,9 @@ public:
     void addActiveScriptWrappable(ActiveScriptWrappable*);
     const ActiveScriptWrappableSet* activeScriptWrappables() const { return m_activeScriptWrappables.get(); }
 
+    void setScriptWrappableVisitor(std::unique_ptr<ScriptWrappableVisitor> visitor) { m_scriptWrappableVisitor = std::move(visitor); }
+    ScriptWrappableVisitor* scriptWrappableVisitor() { return m_scriptWrappableVisitor.get(); }
+
 private:
     V8PerIsolateData();
     ~V8PerIsolateData();
@@ -188,6 +192,7 @@ private:
     OwnPtr<ThreadDebugger> m_threadDebugger;
 
     Persistent<ActiveScriptWrappableSet> m_activeScriptWrappables;
+    std::unique_ptr<ScriptWrappableVisitor> m_scriptWrappableVisitor;
 };
 
 } // namespace blink