- Electron version: 1.2.8
- Operating system: Windows

Hi,

I've been trying to get a context menu containing some [predefined web contents roles](https://github.com/electron/electron/blob/master/lib/browser/api/menu-item-roles.js#L17) working for an application where we have multiple windows simultaneously. I've noticed that when a context menu is opened for a window that was created later than others, the role commands don't seem to execute when clicked. However, if don't use a role and instead define a click handler that calls the command on the web contents manually, it behaves normally.

I've been doing some digging and it seems that the reason is because, for a role, [`electron.webContents.getFocusedWebContents`](https://github.com/electron/electron/blob/master/lib/browser/api/web-contents.js#L257) is used to determine which web contents to call the command on (see [menu.js](https://github.com/electron/electron/blob/master/lib/browser/api/menu.js#L121)).

This function iterates through all existing web contents, then returns the first in the collection that is in a `webview`, otherwise the first that returns `true` from `contents.isFocused()`. However, it seems to be entirely possible that there are web contents other than the one that the context menu was raised for, who think they are focused (or perhaps are within a `webview`), and who were created earlier and therefore appear earlier in the collection.

This means there are situations when the 'wrong' web contents is returned from `getFocusedWebContents`, and therefore the role command is called on that 'wrong' web contents, which leads to the unexpected behaviour described above.

Is this a bug? And if so, is there a fix and/or workaround for this? I'm happy to contribute a PR if needed.

atom/browser/api/atom_api_web_contents.cc
Emit("media-paused");
}
void WebContents::DidChangeThemeColor(SkColor theme_color) {
  std::string hex_theme_color = base::StringPrintf("#%02X%02X%02X",
    SkColorGetR(theme_color),
    SkColorGetG(theme_color),
    SkColorGetB(theme_color));
  Emit("did-change-theme-color", hex_theme_color);
}
void WebContents::DocumentLoadedInFrame(
    content::RenderFrameHost* render_frame_host) {
  if (!render_frame_host->GetParent())
    Emit("dom-ready");
}
void WebContents::DidFinishLoad(content::RenderFrameHost* render_frame_host,
                                const GURL& validated_url) {
  bool is_main_frame = !render_frame_host->GetParent();
  Emit("did-frame-finish-load", is_main_frame);
  if (is_main_frame)
    Emit("did-finish-load");
}
void WebContents::DidFailLoad(content::RenderFrameHost* render_frame_host,
                              const GURL& url,
                              int error_code,
                              const base::string16& error_description,
                              bool was_ignored_by_handler) {
  bool is_main_frame = !render_frame_host->GetParent();
  Emit("did-fail-load", error_code, error_description, url, is_main_frame);
}
void WebContents::DidStartLoading() {