Bug 1358053 - Remove DataSourceSurface assertion when doing snapshot in WebGL; r=jgilbert

MozReview-Commit-ID: 6LhmY1ouNZ9

--HG--
extra : rebase_source : 91511c1aa2f403862c8341b404a6a09d889de963

dom/canvas/ImageBitmap.cpp

@@ -868,10 +868,6 @@ ImageBitmap::CreateInternal(nsIGlobalObject* aGlobal, HTMLCanvasElement& aCanvas
   if ((aCanvasEl.GetCurrentContextType() == CanvasContextType::WebGL1 ||
        aCanvasEl.GetCurrentContextType() == CanvasContextType::WebGL2) &&
       aCropRect.isSome()) {
-    // The _surface_ must be a DataSourceSurface.
-    MOZ_ASSERT(surface->IsDataSourceSurface(),
-               "The snapshot SourceSurface from WebGL rendering contest is not \
-               DataSourceSurface.");
     RefPtr<DataSourceSurface> dataSurface = surface->GetDataSurface();
     croppedSurface = CropAndCopyDataSourceSurface(dataSurface, cropRect);
     cropRect.MoveTo(0, 0);