[idb] Remove outdated comment

The comment does not make sense any more after
https://crrev.com/c/2013046. It should have been removed together with
that CL.

R=jsbell@chromium.org

No-Try: true
Change-Id: I7fcaa85f66377bbefe3527313e7a6f72ddca9a91
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2014923
Auto-Submit: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Joshua Bell <jsbell@chromium.org>
Reviewed-by: Joshua Bell <jsbell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734036}

third_party/blink/renderer/modules/indexeddb/idb_value_wrapping.cc

@@ -87,9 +87,6 @@ void IDBValueWrapper::Clone(ScriptState* script_state, ScriptValue* clone) {
   DCHECK(!done_cloning_) << __func__ << " called after DoneCloning()";
 #endif  // DCHECK_IS_ON()
 
-  // It is safe to unconditionally enable WASM module decoding because the
-  // relevant checks were already performed in SerializedScriptValue::Serialize,
-  // called by the IDBValueWrapper constructor.
   *clone = DeserializeScriptValue(script_state, serialized_value_.get(),
                                   &blob_info_);
 }