Bug 1761002 - Restore the clip rect in webrenderized images. r=mstange

In bug 1758942 there was a bit of clipping logic for webrenderized svg images that was removed because we didn't know what it was useful for.

I still don't quite know, other than that it caused layout/reftests/svg/image/image-preserveAspectRatio-01-raster.svg and layout/reftests/svg/image/image-preserveAspectRatio-02-raster.svg to start failing when the gfx.webrender.svg-images pref is enabled, so let's revert it.

Depends on D141847

Differential Revision: https://phabricator.services.mozilla.com/D141848

layout/svg/SVGImageFrame.cpp

@@ -497,7 +497,16 @@ bool SVGImageFrame::CreateWebRenderCommands(
                                                       appUnitsPerCSSPixel);
   appRect += toReferenceFrame;
   auto destRect = LayoutDeviceRect::FromAppUnits(appRect, appUnitsPerDevPx);
+  auto clipRect = destRect;
+
   if (StyleDisplay()->IsScrollableOverflow()) {
+    // Apply potential non-trivial clip
+    auto cssClip = SVGUtils::GetClipRectForFrame(this, 0, 0, width, height);
+    auto appClip =
+        nsLayoutUtils::RoundGfxRectToAppRect(cssClip, appUnitsPerCSSPixel);
+    appClip += toReferenceFrame;
+    clipRect = LayoutDeviceRect::FromAppUnits(appClip, appUnitsPerDevPx);
+
     // Apply preserveAspectRatio
     if (mImageContainer->GetType() == imgIContainer::TYPE_RASTER) {
       int32_t nativeWidth, nativeHeight;
@@ -611,7 +620,7 @@ bool SVGImageFrame::CreateWebRenderCommands(
 
   Maybe<ImageIntRegion> region;
   IntSize decodeSize = nsLayoutUtils::ComputeImageContainerDrawingParameters(
-      mImageContainer, this, destRect, destRect, aSc, flags, svgContext,
+      mImageContainer, this, destRect, clipRect, aSc, flags, svgContext,
       region);
 
   RefPtr<image::WebRenderImageProvider> provider;
@@ -644,7 +653,7 @@ bool SVGImageFrame::CreateWebRenderCommands(
     if (provider) {
       aManager->CommandBuilder().PushImageProvider(aItem, provider, drawResult,
                                                    aBuilder, aResources,
-                                                   destRect, destRect);
+                                                   destRect, clipRect);
     }
 
     nsDisplayItemGenericImageGeometry::UpdateDrawResult(aItem, drawResult);