Make a couple helper methods in SkyQueryEnvironment public.

FIXED=31439098

--
MOS_MIGRATED_REVID=133751771
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 826ccdf..4de4f87 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
@@ -711,7 +711,7 @@
     }
   };
 
-  private Map<SkyKey, Target> makeTargetsFromSkyKeys(Iterable<SkyKey> keys)
+  public Map<SkyKey, Target> makeTargetsFromSkyKeys(Iterable<SkyKey> keys)
       throws InterruptedException {
     Multimap<SkyKey, SkyKey> packageKeyToTargetKeyMap = ArrayListMultimap.create();
     for (SkyKey key : keys) {
@@ -747,6 +747,11 @@
         }
       };
 
+  /** A strict (i.e. non-lazy) variant of {@link #makeTransitiveTraversalKeys}. */
+  public static Iterable<SkyKey> makeTransitiveTraversalKeysStrict(Iterable<Target> targets) {
+    return ImmutableList.copyOf(makeTransitiveTraversalKeys(targets));
+  }
+
   private static Iterable<SkyKey> makeTransitiveTraversalKeys(Iterable<Target> targets) {
     return Iterables.transform(targets, TARGET_TO_SKY_KEY);
   }