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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/api/electron_api_web_contents.cc
content::RenderFrameHost* render_frame_host) {
  if (render_frame_host == ontents()->GetMainFrame()) {
    Emit("ready-to-show");
  }
}
void WebContents::ReceivePostMessage(
    const std::string& channel,
    blink::TransferableMessage message,
    content::RenderFrameHost* render_frame_host) {
  v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
  v8::HandleScope handle_scope(isolate);
  auto wrapped_ports =
      MessagePort::EntanglePorts(isolate, std::move(message.ports));
  v8::Local<v8::Value> message_value =
      electron::DeserializeV8Value(isolate, message);
  EmitWithSender("-ipc-ports", render_frame_host,
                 electron::mojom::ElectronBrowser::InvokeCallback(), false,
                 channel, message_value, std::move(wrapped_ports));
}
void WebContents::MessageSync(