title: Canvas drawing not loading in puppeteer
body: <p>I need to generate snapshots for seo. 
  I am using puppeteer(headless chrome) for this purpose. 
  On main page i have a canvas, on which i start to draw once the component has mounted (my main site is in react).</p>
  
  <p>Issue is that when i get the html from puppeteer, the drawing on the canvas is not there. </p>
  
  <p>In puppeteer code i wait till the content is not loaded.</p>
  
  <pre><code>html = await page.content()
  </code></pre>
  
  <p>How can i make puppeteer wait till the point canvas is not painted.</p>