Keep a persistent handle for the bindings classes to avoid repeated lookups that involve performing…

Source/bindings/dart/DartDOMWrapper.h

Index: Source/bindings/dart/DartDOMWrapper.h
diff --git a/Source/bindings/dart/DartDOMWrapper.h b/Source/bindings/dart/DartDOMWrapper.h
index aea7c6e8c97f775f658f8ef5d9d3d728629e1fc9..ab8ba74a5949599778dddeec62e922b1a7b4f3cf 100644
--- a/Source/bindings/dart/DartDOMWrapper.h
+++ b/Source/bindings/dart/DartDOMWrapper.h
@@ -52,9 +52,12 @@ struct DartDOMWrapperTraits;
 class DartDOMWrapper {
 public:
     template <class WebKitClass>
-    static Dart_Handle newWrapper(const char* className, const char* libraryName, WebKitClass* domObject)
+    static Dart_Handle newWrapper(const char* className, const char* libraryName, intptr_t cid, WebKitClass* domObject)
     {
-        Dart_Handle wrapper = instantiateWrapper(className, libraryName);
+
+        Dart_Handle type = dartClass(className, libraryName, cid);
+        ASSERT(!Dart_IsError(type));
+        Dart_Handle wrapper = Dart_Allocate(type);
         writeNativePointer(wrapper, kNativeImplementationIndex, domObject);
         return wrapper;
     }
@@ -62,12 +65,16 @@ public:
     template <class BindingsClass>
     static Dart_Handle toDart(typename BindingsClass::NativeType* domObject)
     {
-        return toDartWithClassName<BindingsClass>(domObject, BindingsClass::dartImplementationClassName, BindingsClass::dartImplementationLibraryName);
+        return toDartWithClassName<BindingsClass>(
+            domObject,
+            BindingsClass::dartImplementationClassName,
+            BindingsClass::dartImplementationLibraryName,
+            BindingsClass::dartClassId);
     }
 
     template <class BindingsClass>
     static Dart_Handle toDartWithClassName(typename BindingsClass::NativeType* domObject,
-        const char* className, const char* libraryName)
+        const char* className, const char* libraryName, intptr_t cid)
     {
         typedef DartDOMWrapperTraits<BindingsClass> Traits;
 
@@ -78,7 +85,7 @@ public:
         if (oldInstance)
             return oldInstance;
 
-        Dart_Handle newInstance = newWrapper(className, libraryName, domObject);
+        Dart_Handle newInstance = newWrapper(className, libraryName, cid, domObject);
         return associateWrapper<BindingsClass>(domObject, newInstance);
     }
 
@@ -179,7 +186,13 @@ public:
     template <class BindingsClass>
     static bool instanceOf(Dart_Handle wrapper)
     {
-        return instanceOf(BindingsClass::dartImplementationClassName, BindingsClass::dartImplementationLibraryName, wrapper);
+        Dart_Handle type = dartClass<BindingsClass>();
+
+        bool isInstanceOf = false;
+        Dart_Handle result = Dart_ObjectIsType(wrapper, type, &isInstanceOf);
+        if (Dart_IsError(result))
+            return false;
+        return isInstanceOf;
     }
 
     template <class WebKitClass>
@@ -220,9 +233,14 @@ private:
         kNativeFieldCount
     };
 
-    static Dart_Handle instantiateWrapper(const char* className, const char* libraryName);
-    static bool instanceOf(const char* dartImplementationClassName,
-            const char* dartImplementationLibraryName, Dart_Handle wrapper);
+    static Dart_Handle dartClass(const char* dartImplementationClassName,
+        const char* dartImplementationLibraryName, intptr_t classIndex);
+
+    template <class BindingsClass>
+    static Dart_Handle dartClass()
+    {
+        return dartClass(BindingsClass::dartImplementationClassName, BindingsClass::dartImplementationLibraryName, BindingsClass::dartClassId);
+    }
 
     static void writeNativePointer(Dart_Handle wrapper, int index, void* pointer)
     {