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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
void InspectableWebContents::InspectedURLChanged(const std::string& url) {
  if (managed_devtools_web_contents_)
    view_->SetTitle(
        base::UTF8ToUTF16(base::StringPrintf(kTitleFormat, url.c_str())));
}
void InspectableWebContents::LoadNetworkResource(DispatchCallback callback,
                                                 const std::string& url,
                                                 const std::string& headers,
                                                 int stream_id) {
  GURL gurl(url);
  if (!gurl.is_valid()) {
    base::DictionaryValue response;
    response.SetInteger("statusCode", net::HTTP_NOT_FOUND);
    std::move(callback).Run(&response);
    return;
  }
  
  net::NetworkTrafficAnnotationTag traffic_annotation =
      net::DefineNetworkTrafficAnnotation("devtools_network_resource", R"(
        semantics {
          sender: "Developer Tools"
          description:
            "When user opens Developer Tools, the browser may fetch additional "
            "resources from the network to enrich the debugging experience "
            "(e.g. source map resources)."
          trigger: "User opens Developer Tools to debug a web page."
          data: "Any resources requested by Developer Tools."
          destination: WEBSITE
        }