binding: Simplify v8DateOrNaN().

isfinite() check is unnecessary here because -Infinity and +Infinity will be
converted to NaN in i::JSDate::New(), which is called by v8::Date::New.

This CL has no behavior changes.

Review-Url: https://codereview.chromium.org/2602723002
Cr-Commit-Position: refs/heads/master@{#440745}

third_party/WebKit/Source/bindings/core/v8/V8Binding.h

@@ -658,9 +658,7 @@ inline double toCoreDate(v8::Isolate* isolate,
 inline v8::MaybeLocal<v8::Value> v8DateOrNaN(v8::Isolate* isolate,
                                              double value) {
   ASSERT(isolate);
-  return v8::Date::New(
-      isolate->GetCurrentContext(),
-      std::isfinite(value) ? value : std::numeric_limits<double>::quiet_NaN());
+  return v8::Date::New(isolate->GetCurrentContext(), value);
 }
 
 // FIXME: Remove the special casing for NodeFilter and XPathNSResolver.