Remove dead code from TreeArtifactValue.

PiperOrigin-RevId: 328435075

src/main/java/com/google/devtools/build/lib/skyframe/TreeArtifactValue.java

@@ -90,21 +90,6 @@ public interface MultiBuilder {
     MultiBuilder setArchivedRepresentation(
         ArchivedTreeArtifact archivedArtifact, FileArtifactValue metadata);
 
-    /**
-     * Make sure the builder will inject a {@link TreeArtifactValue} for a given {@linkplain
-     * SpecialArtifact tree artifact}.
-     *
-     * <p>Convenience method allowing to construct potentially empty {@link TreeArtifactValue} with
-     * a {@link MultiBuilder}.
-     *
-     * <p>There is no need to call this method before {@link #putChild(TreeFileArtifact,
-     * FileArtifactValue)} or {@link #setArchivedRepresentation(ArchivedTreeArtifact,
-     * FileArtifactValue)} since both methods implicitly make sure that the {@link
-     * TreeArtifactValue} will be created for the related {@linkplain SpecialArtifact parent tree
-     * artifact}.
-     */
-    MultiBuilder addTreeArtifact(SpecialArtifact treeArtifact);
-
     /**
      * For each unique parent seen by this builder, passes the aggregated metadata to {@link
      * TreeArtifactInjector#injectTree}.
@@ -494,14 +479,6 @@ public MultiBuilder setArchivedRepresentation(
       return this;
     }
 
-    @Override
-    public MultiBuilder addTreeArtifact(SpecialArtifact treeArtifact) {
-      Preconditions.checkArgument(
-          treeArtifact.isTreeArtifact(), "Not a tree artifact: %s", treeArtifact);
-      map.computeIfAbsent(treeArtifact, Builder::new);
-      return this;
-    }
-
     @Override
     public void injectTo(TreeArtifactInjector treeInjector) {
       map.forEach((parent, builder) -> treeInjector.injectTree(parent, builder.build()));
@@ -537,14 +514,6 @@ public MultiBuilder setArchivedRepresentation(
       return this;
     }
 
-    @Override
-    public MultiBuilder addTreeArtifact(SpecialArtifact treeArtifact) {
-      Preconditions.checkArgument(
-          treeArtifact.isTreeArtifact(), "Not a tree artifact: %s", treeArtifact);
-      children.computeIfAbsent(treeArtifact, ignored -> new ConcurrentHashMap<>());
-      return null;
-    }
-
     @Override
     public void injectTo(TreeArtifactInjector treeInjector) {
       children.forEach(