bindings: Add assersion in v8AtomicString

Source/bindings/core/v8/V8Binding.h

Index: Source/bindings/core/v8/V8Binding.h
diff --git a/Source/bindings/core/v8/V8Binding.h b/Source/bindings/core/v8/V8Binding.h
index c71b05f6920efc9bb12039a9f7348fd6f3cd3352..f07da9d7e794fffcf89aba0cb89f7caa7e84ec01 100644
--- a/Source/bindings/core/v8/V8Binding.h
+++ b/Source/bindings/core/v8/V8Binding.h
@@ -354,6 +354,9 @@ inline v8::Handle<v8::String> v8AtomicString(v8::Isolate* isolate, const char* s
     v8::Local<v8::String> value;
     if (LIKELY(v8::String::NewFromUtf8(isolate, str, v8::NewStringType::kInternalized, length).ToLocal(&value)))
         return value;
+    // Immediately crashes when NewFromUtf8() fails because it only fails the
+    // given str is too long.
+    RELEASE_ASSERT_NOT_REACHED();
     return v8::String::Empty(isolate);
 }