Loosen visibility and finality of *QueryEnvironment fields.

--
MOS_MIGRATED_REVID=138534021
diff --git a/src/main/java/com/google/devtools/build/lib/query2/SkyQueryEnvironment.java b/src/main/java/com/google/devtools/build/lib/query2/SkyQueryEnvironment.java
index 1f2bcd7..2bfd5e7 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/SkyQueryEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/SkyQueryEnvironment.java
@@ -124,11 +124,11 @@
   private static final Logger LOG = Logger.getLogger(SkyQueryEnvironment.class.getName());
 
   private final BlazeTargetAccessor accessor = new BlazeTargetAccessor(this);
-  private final int loadingPhaseThreads;
-  private final WalkableGraphFactory graphFactory;
-  private final List<String> universeScope;
+  protected final int loadingPhaseThreads;
+  protected final WalkableGraphFactory graphFactory;
+  protected final List<String> universeScope;
   protected final String parserPrefix;
-  private final PathPackageLocator pkgPath;
+  protected final PathPackageLocator pkgPath;
   private final int queryEvaluationParallelismLevel;
 
   // The following fields are set in the #beforeEvaluateQuery method.