Remove use of a V8 isolate outside of bindings code in ImageBitmapFactories.cpp.

Review URL: https://codereview.chromium.org/197283042

git-svn-id: svn://svn.chromium.org/blink/trunk@170089 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/modules/imagebitmap/ImageBitmapFactories.cpp

@@ -70,8 +70,7 @@ static ScriptPromise fulfillImageBitmap(ExecutionContext* context, PassRefPtrWil
     if (imageBitmap) {
         resolver->resolve(imageBitmap);
     } else {
-        v8::Isolate* isolate = ScriptState::current()->isolate();
-        resolver->reject(ScriptValue(v8::Null(isolate), isolate));
+        resolver->reject(ScriptValue::createNull());
     }
     return promise;
 }
@@ -316,9 +315,8 @@ void ImageBitmapFactories::ImageBitmapLoader::loadBlobAsync(ExecutionContext* co
 
 void ImageBitmapFactories::ImageBitmapLoader::rejectPromise()
 {
-    v8::Isolate* isolate = m_scriptState->isolate();
     ScriptScope scope(m_scriptState);
-    m_resolver->reject(ScriptValue(v8::Null(isolate), isolate));
+    m_resolver->reject(ScriptValue::createNull());
     m_factory->didFinishLoading(this);
 }