Bug 1410239 - Ensure the mozPrintCallback gets invoked when painting canvases. r=jrmuizel

MozReview-Commit-ID: ADKQb3vVuPs

--HG--
extra : rebase_source : 1f9c4ee6ca3fbdfdb300052736e20af676df4869

layout/generic/nsHTMLCanvasFrame.cpp

@@ -130,6 +130,8 @@ public:
                                        nsDisplayListBuilder* aDisplayListBuilder) override
   {
     HTMLCanvasElement* element = static_cast<HTMLCanvasElement*>(mFrame->GetContent());
+    element->HandlePrintCallback(mFrame->PresContext()->Type());
+
     switch(element->GetCurrentContextType()) {
       case CanvasContextType::Canvas2D:
       case CanvasContextType::WebGL1:

layout/reftests/pagination/reftest.list

@@ -103,7 +103,7 @@ fuzzy-if(skiaContent,1,23) == resize-reflow-001.html resize-reflow-001.ref.html
 == 115199-2a.html 115199-2-ref.html
 == 115199-2b.html 115199-2-ref.html
 == 652178-1.html 652178-1-ref2.html
-fuzzy-if(cocoaWidget,1,5000) skip-if(webrender) == 745025-1.html 745025-1-ref.html
+fuzzy-if(cocoaWidget,1,5000) == 745025-1.html 745025-1-ref.html
 == 820496-1.html 820496-1-ref.html
 
 # NOTE: These tests don't yet rigorously test what they're