... because it is no longer used.
Created attachment 25743 [details] Remove unused Completion.h in CanvasRenderingContext2D.cpp easy-peasy.
Created attachment 25744 [details] remvoe completion.h v2 now with a ChangeLog entry!
Comment on attachment 25744 [details] remvoe completion.h v2 r=me
Committed in r39000.