Bug 1723741 - Fix how SVG images in blob recordings would always be transparent. r=gfx-reviewers,jrmuizel

This occurred due to a signature mismatch with
gfxUtils::DrawPixelSnapped. A previous patch in bug 1712855 put the
wrong field in the opacity parameter. It implicitly converted a bool to
a float silently, causing the opacity to be 0.0.

Differential Revision: https://phabricator.services.mozilla.com/D121628

image/SourceSurfaceBlobImage.cpp

@@ -213,7 +213,8 @@ Maybe<BlobImageKeyData> SourceSurfaceBlobImage::RecordDrawing(
 
     gfxUtils::DrawPixelSnapped(ctx, svgDrawable, SizeDouble(mSize), region,
                                SurfaceFormat::OS_RGBA, SamplingFilter::POINT,
-                               mImageFlags, /* aUseOptimalFillOp */ false);
+                               mImageFlags, /* aOpacity */ 1.0,
+                               /* aUseOptimalFillOp */ false);
   }
 
   recorder->FlushItem(imageRectOrigin);