Steps to reproduce

Tell us about your environment:

• Puppeteer version: 1.5.0
• Platform / OS version: Mac OS X 10.11.6
• URLs (if applicable):
• Node.js version: 9.4.0

What steps will reproduce the problem?

1. Go to https://try-puppeteer.appspot.com/. Use the following code:

const browser = await puppeteer.launch();

const page = await browser.newPage();
await page.goto('https://www.google.de/maps/@52.5197103,13.4068538,16.11z');

await page.setViewport({
    width: 800,
    height: 600,
    deviceScaleFactor: 3
});

await page.waitFor(5000);

await page.screenshot({path: 'screenshot.png'});

await browser.close();

2. Check screenshot and compare it against what you can see while browsing https://openlayersbook.github.io/ch06-styling-vector-layers/example-03.html on a retina display device in a real Chrome.

What is the expected result?
Sharp canvas.

What happens instead?
Blurry canvas.