Chrome Extension API: chrome.tabs.captureVisibleTab on Background Page to Content Script

Question

My overall goal was to take a screenshot via the background page using:

http://developer.chrome.com/extensions/tabs.html#method-captureVisibleTab

and pass it

Answer 1

Use chrome.tabs.sendMessage

background page:

chrome.runtime.onMessage.addListener(
    function(request, sender, sendResponse) {
        chrome.tabs.captureVisibleTab(
            null,
            {},
            function(dataUrl)
            {
                sendResponse({imgSrc:dataUrl});
            }
        ); //remember that captureVisibleTab() is a statement
        return true;
    }
);

content script

chrome.runtime.sendMessage({msg: "capture"}, function(response) {
  console.log(response.dataUrl);
});