Canvas should only resize when canvas width and height attributes are changed
Another odd characteristic of this bug happens if you open (for instance):
and then hit cmd-+. The planets get smaller. This is happening because I am looking at the CSS size to set the canvas, but at the canvas width and height to set the viewport. The canvas size doesn't change but the css size gets bigger, so the viewport is small relative to the canvas size.
This is all fixed by not changing the canvas based on the CSS size, which is what fixing this bug will do.
Created attachment 46844 [details]
Attachment 46844 [details] did not pass style-queue:
Failed to run "WebKitTools/Scripts/check-webkit-style" exit_code: 1
WebCore/html/HTMLCanvasElement.cpp:277: Tests for true/false, null/non-null, and zero/non-zero should all be done without equality comparisons. [readability/comparison_to_zero] 
WebCore/html/HTMLCanvasElement.cpp:277: Use 0 instead of NULL. [readability/null] 
Total errors found: 2
If any of these errors are false positives, please file a bug against check-webkit-style.
Landed in http://trac.webkit.org/changeset/53434