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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
v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
  v8::Locker locker(isolate);
  v8::HandleScope handle_scope(isolate);
  devtools_ontents_.Reset();
  Emit("devtools-closed");
}
void WebContents::DevToolsResized() {
  for (ExtendedWebContentsObserver& observer : observers_)
    observer.OnDevToolsResized();
}
void WebContents::SetOwnerWindow(NativeWindow* owner_window) {
  SetOwnerWindow(GetWebContents(), owner_window);
}
void WebContents::SetOwnerWindow(content::WebContents* ontents,
                                 NativeWindow* owner_window) {
  if (owner_window) {
    owner_window_ = owner_window->GetWeakPtr();
    NativeWindowRelay::CreateForWebContents(ontents,
                                            owner_window->GetWeakPtr());
  } else {
    owner_window_ = nullptr;
    ontents->RemoveUserData(NativeWindowRelay::UserDataKey());
  }
#if BUILDFLAG(ENABLE_OSR)
  auto* osr_wcv = GetOffScreenWebContentsView();
  if (osr_wcv)
    osr_wcv->SetNativeWindow(owner_window);
#endif
}
content::WebConbContents::GetWebContents() const {