Bug 1513683 - Update webrender to commit bf98e0cbde3ac885f55ff536ace139e1dc4f080f (WR PR #3396). r=kats

https://github.com/servo/webrender/pull/3396

Differential Revision: https://phabricator.services.mozilla.com/D14311

--HG--
extra : moz-landing-system : lando

gfx/webrender_bindings/revision.txt

@@ -1 +1 @@
-6f993ede3a062777d3067006537bab140702b669
+bf98e0cbde3ac885f55ff536ace139e1dc4f080f

gfx/wr/webrender/src/batch.rs

@@ -1040,7 +1040,7 @@ impl AlphaBatchBuilder {
 
                                         let key = BatchKey::new(
                                             kind,
-                                            non_segmented_blend_mode,
+                                            BlendMode::None,
                                             BatchTextures::color(cache_item.texture_id),
                                         );
 

gfx/wr/webrender/src/picture.rs

@@ -2189,11 +2189,15 @@ impl PicturePrimitive {
                 match tile_cache.dirty_region {
                     Some(ref dirty_region) => {
                         // Texture cache descriptor for each tile.
+                        // TODO(gw): If / when we start to use tile caches with
+                        //           clip masks and/or transparent backgrounds,
+                        //           we will need to correctly select an opacity
+                        //           here and a blend mode in batch.rs.
                         let descriptor = ImageDescriptor::new(
                             TILE_SIZE_DP,
                             TILE_SIZE_DP,
                             ImageFormat::BGRA8,
-                            false,          // TODO(gw): Detect when background color is opaque!
+                            true,
                             false,
                         );