Chrome Extension: Sending a message to the page loaded in a specific iframe
问题 I'm working on a Chrome extension to (among other things) support a page with multiple iframes, each of which loads a page from some other domain. I need to send a msg to the page loaded a specific one of those iframes. The top-level page and the pages in the iframe each have their own content scripts, so the full messaging API is available. From the top page, when I do chrome.runtime.sendMessage(), all the iframes get it (as does the top window, but it's easy for its content script to know