Hi, sorry to the OP if this comes as a thread hijack, but looking at the example that you post on google, Ashley, I came across a problem that was happening to me sometimes in Chrome. After many page reloads (F5) on Chrome the canvas image starts to get blurry ad infinitum. I was not able to reproduce it in a "reproducible manner" before, so I did not bring it up, but doing what you say on the post happens to make it start, and hitting F5 get the problem all the way through.
Don't know if it is entirely related to the issue you are describing, but when the blurriness is at max I got this at Chrome console:
GL_INVALID_OPERATION : glGetRenderbufferStorageMultisample: no renderbuffer bound /labs/chromewebglbug/:1
GL_INVALID_OPERATION : glFramebufferRenderbuffer: no framebuffer bound /labs/chromewebglbug/:1
GL_INVALID_OPERATION : glFramebufferTexture2D: no framebuffer bound. /labs/chromewebglbug/:1
Don't know if it helps with the issue in google forums in some way. Will star the issue to get it promoted, anyway! Sorry to the OP again!