Minor optimization to v8::internal::Factory::InternalizeOneByteString.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index e2637ece1e32fd57faf99913c0ca4c5f54746aa1..0d22a3e229098a0aa75befda347bb011df158b3f 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -271,9 +271,27 @@ Handle<String> Factory::InternalizeUtf8String(Vector<const char> string) {
   return InternalizeStringWithKey(&key);
 }
 
+namespace {
+
+class OneByteStringKeyExpectingSequential final : public OneByteStringKey {
+  using OneByteStringKey::OneByteStringKey;
+
+  bool IsMatch(Object* string) final {
+    if (V8_LIKELY(StringShape(String::cast(string)).IsSequentialOneByte())) {
+      SeqOneByteString* seq_one_byte = SeqOneByteString::cast(string);
+      return seq_one_byte->length() == string_.length() &&
+             memcmp(seq_one_byte->GetChars(), string_.start(),
+                    string_.length()) == 0;
+    }
+    return OneByteStringKey::IsMatch(string);
+  }
+};
+
+}  // namespace
 
 Handle<String> Factory::InternalizeOneByteString(Vector<const uint8_t> string) {
-  OneByteStringKey key(string, isolate()->heap()->HashSeed());
+  OneByteStringKeyExpectingSequential key(string,
+                                          isolate()->heap()->HashSeed());
   return InternalizeStringWithKey(&key);
 }