Use StringView for String and AtomicString operator==.

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

Index: third_party/WebKit/Source/bindings/core/v8/V8Binding.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8Binding.cpp b/third_party/WebKit/Source/bindings/core/v8/V8Binding.cpp
index db5b534047d62eba6e04f91b3045d27314f5dc6c..2511fed997fea08cadb67a20585b8969ea65230d 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8Binding.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8Binding.cpp
@@ -869,7 +869,8 @@ bool isValidEnum(const String& value,
                  const String& enumName,
                  ExceptionState& exceptionState) {
   for (size_t i = 0; i < length; ++i) {
-    if (value == validValues[i])
+    // Avoid the strlen inside String::operator== (because of the StringView).
+    if (WTF::equal(value.impl(), validValues[i]))
       return true;
   }
   exceptionState.throwTypeError("The provided value '" + value +