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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
const std::string& browser_id,
                                             const std::string& url) {
  std::move(callback).Run(nullptr);
}
void InspectableWebContents::GetPreferences(DispatchCallback callback) {
  const base::DictionaryValue* prefs =
      pref_service_->GetDictionary(kDevToolsPreferences);
  std::move(callback).Run(prefs);
}
void InspectableWebContents::SetPreference(const std::string& name,
                                           const std::string& value) {
  DictionaryPrefUpdate update(pref_service_, kDevToolsPreferences);
  update.Get()->SetKey(name, base::Value(value));
}
void InspectableWebContents::RemovePreference(const std::string& name) {
  DictionaryPrefUpdate update(pref_service_, kDevToolsPreferences);
  update.Get()->RemoveWithoutPathExpansion(name, nullptr);
}
void InspectableWebContents::ClearPreferences() {
  DictionaryPrefUpdate update(pref_service_, kDevToolsPreferences);
  update.Get()->Clear();
}
void InspectableWebContents::ConnectionReady() {}
void InspectableWebContents::RegisterExtensionsAPI(const std::string& origin,
                                                   const std::string& script) {
  extensions_api_[origin + "/"] = script;
}
void InspectableWebContents::HandleMessageFromDevToolsFrontend(