[giow] (3) Make the spec throw an exception for broken images drawn into canvas, like Firefox and IE do today.
Affected topics: Canvas

git-svn-id: http://svn.whatwg.org/webapps@8131 340c8d12-0b0e-0410-8428-c7bf67bfef74
[giow] (1) Allow UAs to use algorithms other than nearest-neighbour when scaling images down.
Affected topics: Canvas

git-svn-id: http://svn.whatwg.org/webapps@8132 340c8d12-0b0e-0410-8428-c7bf67bfef74