Loosen visibility of ASTFileLookupValue.

--
PiperOrigin-RevId: 147559691
MOS_MIGRATED_REVID=147559691
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupValue.java
index 27430e9..fa425bc 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupValue.java
@@ -21,11 +21,11 @@
 import com.google.devtools.build.skyframe.SkyValue;
 
 /**
- * A value that represents an AST file lookup result. There are two subclasses: one for the
- * case where the file is found, and another for the case where the file is missing (but there
- * are no other errors).
+ * A value that represents an AST file lookup result. There are two subclasses: one for the case
+ * where the file is found, and another for the case where the file is missing (but there are no
+ * other errors).
  */
-abstract class ASTFileLookupValue implements SkyValue {
+public abstract class ASTFileLookupValue implements SkyValue {
   public abstract boolean lookupSuccessful();
   public abstract BuildFileAST getAST();
   public abstract String getErrorMsg();
@@ -94,7 +94,7 @@
     return new ASTLookupWithFile(ast);
   }
 
-  static SkyKey key(Label astFileLabel) {
+  public static SkyKey key(Label astFileLabel) {
     return SkyKey.create(SkyFunctions.AST_FILE_LOOKUP, astFileLabel);
   }
 }