In a Chrome extension, is there a way to globally trap/handle Javascript errors occurring in a content-script? (e.g. for submission to a Javascript error tracking service like bugsnag)

Ideally, I would setup a global window.onerror handler at the top of the content script. But it's not working properly in Chrome 40: the error is caught, but the information supplied is useless: a message of 'Script error' and no url, lineNumber, column or error object with stack.

I created a test extension to show this busted behaviour for content scripts. Details below. Interesting findings:

• window.onerror works correctly in a background script, with full error information
• window.onerror on the hosting webpage can also see the error thrown by an extension content script (but the error doesn't contain any useful info either)

Reproducing busted window.onerror for Chrome extension content script.

In a new folder, create manifest.json, content-script.js and background-script.js. Then load into Chrome via Window > Extensions > Load unpacked Extension.

• To see the busted window.onerror info for a content-script error, reload a webpage and look at the devtools console

manifest.json

{
    "name": "Chrome extension content-script errors test",
    "manifest_version": 2,
    "version": "0.0.1",
    "background": {
      "scripts": [ "background-script.js" ]
    },
    "content_scripts": [{
        "matches": ["<all_urls>"],
        "js": ["content-script.js"]
    }]
}

content-script.js

window.onerror = function (errorMsg, url, lineNumber, column, errorObj) {
    console.log('Caught content script error');
    console.log('errorMsg: ' + errorMsg);
    console.log('url: ' + url);
    console.log('lineNumber: ' + column);
    console.log('column: ' + column);
    console.log('errorObj follows:');
    console.log(errorObj);
    return true;
};

console.log('I am a content script, about to throw an error');
throw new Error('Is this error caught?');

background-script.js

window.onerror = function (errorMsg, url, lineNumber, column, errorObj) {
    console.log('Caught background script error');
    console.log('errorMsg: ' + errorMsg);
    console.log('url: ' + url);
    console.log('lineNumber: ' + column);
    console.log('column: ' + column);
    console.log('errorObj follows:');
    console.log(errorObj);
    return true;
};

//To see nice window.onerror behaviour for background script..
//Uncomment 2 lines below, reload extension, and look at extension console
//console.log('I am a background script, about to throw an error');
//throw new Error('Is this error caught?');