Backed out changeset d6cca05b4e9f (bug 1217031) for issues in 2d.pattern.image.incomplete.immediate.html

dom/canvas/CanvasRenderingContext2D.cpp

@@ -2174,6 +2174,7 @@ CanvasRenderingContext2D::CreatePattern(const CanvasImageSource& aSource,
       nsLayoutUtils::SFE_WANT_FIRST_FRAME, mTarget);
 
   if (!res.GetSourceSurface()) {
+    aError.Throw(NS_ERROR_NOT_AVAILABLE);
     return nullptr;
   }
 

dom/webidl/CanvasRenderingContext2D.webidl

@@ -69,7 +69,7 @@ interface CanvasRenderingContext2D {
   [NewObject, Throws]
   CanvasGradient createRadialGradient(double x0, double y0, double r0, double x1, double y1, double r1);
   [NewObject, Throws]
-  CanvasPattern? createPattern(CanvasImageSource image, [TreatNullAs=EmptyString] DOMString repetition);
+  CanvasPattern createPattern(CanvasImageSource image, [TreatNullAs=EmptyString] DOMString repetition);
 
   // shadows
            [LenientFloat]