When using chromium I get a red line at the bottom and right side (Not the square red frame set by strict mode), within the rendered web page when viewing some pages requiring WebGL. What does it mean? It usually doesn't appear right away when loading the site and takes a while but even after it appears, the WebGL apps seem to continue working properly.
An example of such a site is http://webglsamples.googlecode.com/hg/lots-o-images/index.html.