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### Issue Details
Electron Version: All Version
Operating System: macOS 10.15.3
Last Known Working Electron version: Never

### Bug
The color picker in devtools does not work.
In devtools if you want to change the colors of the CSS code. When you click on a color a color picker is supposed to appear but it does not appear.

### Screenshots
<img width="1013" alt="Capture d’écran 2020-09-07 à 11 42 44" src="https://user-images.githubusercontent.com/70572698/92374841-988ea280-f100-11ea-96be-afc93f6dd645.png">

shell/browser/ui/inspectable_web_contents.cc
base::Value message) {
  
  if (!embedder_message_dispatcher_) {
    return;
  }
  const std::string* method = nullptr;
  base::Value* params = nullptr;
  if (message.is_dict()) {
    method = message.FindStringKey(kFrontendHostMethod);
    params = message.FindKey(kFrontendHostParams);
  }
  if (!method || (params && !params->is_list())) {
    LOG(ERROR) << "Invalid message was sent to embedder: " << message;
    return;
  }
  base::Value empty_params(base::Value::Type::LIST);
  if (!params) {
    params = &empty_params;
  }
  int id = message.FindIntKey(kFrontendHostId).value_or(0);
  base::ListValue* params_list = nullptr;
  params->GetAsList(&params_list);
  embedder_message_dispatcher_->Dispatch(
      base::BindRepeating(&InspectableWebContents::SendMessageAck,
                          weak_factory_.GetWeakPtr(), id),
      *method, params_list);
}
void InspectableWebContents::DispatchProtocolMessage(