inspector: update inspector_protocol to 8ec18cf

Apply 8ec18cf: "Support STRING16 in the template when converting CBOR
map keys"

Refs: https://chromium.googlesource.com/deps/inspector_protocol/+/8ec18cf0885bef0b5c2a922c5dc3813cbf63e962

We're over 2 years out of date in the tools/inspector_protocol directory
and I have to imagine this will come back to bite us at some point. But
I also don't want to do a huge update all at once, so starting with a
single commit. I might bundle commits together a bit more if this goes
well.

PR-URL: #39614
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

Author: Trott

tools/inspector_protocol/lib/Values_cpp.template

@@ -178,7 +178,12 @@ std::unique_ptr<DictionaryValue> parseMap(
       key = StringUtil::fromUTF8(key_span.data(), key_span.size());
       tokenizer->Next();
     } else if (tokenizer->TokenTag() == cbor::CBORTokenTag::STRING16) {
-      return nullptr;  // STRING16 not supported yet.
+      span<uint8_t> key_span = tokenizer->GetString16WireRep();
+      if (key_span.size() & 1) return nullptr;  // UTF16 is 2 byte multiple.
+      key = StringUtil::fromUTF16(
+          reinterpret_cast<const uint16_t*>(key_span.data()),
+          key_span.size() / 2);
+      tokenizer->Next();
     } else {
       // Error::CBOR_INVALID_MAP_KEY
       return nullptr;