Fix a compile error in indexed_db_leveldb_coding_encodeidbkey_fuzzer.

This was not an issue in release builds, but it's causing failures in
libFuzzer debug builds.

Change-Id: Ic4297a97c3cd6361e778b19f66aa8779bbb89e0b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1875516
Auto-Submit: Martin Barbella <mbarbella@chromium.org>
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708783}

content/browser/indexed_db/indexed_db_leveldb_coding_encodeidbkey_fuzzer.cc

@@ -100,6 +100,6 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   auto decoded_key = std::make_unique<IndexedDBKey>();
   auto result_str_piece = base::StringPiece(result);
   ignore_result(content::DecodeIDBKey(&result_str_piece, &decoded_key));
-  assert(decoded_key.Equals(key));
+  assert(decoded_key->Equals(key));
   return 0;
 }