Convert usages of Predicate to lambda

Change-Id: I9c1c93dd4430ece67956f0dc73a9678433e3e142

gitiles-servlet/src/main/java/com/google/gitiles/CommitData.java

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/CommitData.java b/gitiles-servlet/src/main/java/com/google/gitiles/CommitData.java
index f066d40..d671e43 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/CommitData.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/CommitData.java
@@ -18,7 +18,6 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 
-import com.google.common.base.Predicate;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
@@ -190,18 +189,12 @@
           .toUrl();
     }
 
-    private List<Ref> getRefsById(Repository repo, ObjectId id, final String prefix) {
+    private List<Ref> getRefsById(Repository repo, ObjectId id, String prefix) {
       if (refsById == null) {
         refsById = repo.getAllRefsByPeeledObjectId();
       }
       return FluentIterable.from(firstNonNull(refsById.get(id), ImmutableSet.<Ref>of()))
-          .filter(
-              new Predicate<Ref>() {
-                @Override
-                public boolean apply(Ref ref) {
-                  return ref.getName().startsWith(prefix);
-                }
-              })
+          .filter(r -> r.getName().startsWith(prefix))
           .toSortedList(
               Ordering.natural().onResultOf(r -> r.getName()));
     }

gitiles-servlet/src/main/java/com/google/gitiles/VisibilityCache.java

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/VisibilityCache.java b/gitiles-servlet/src/main/java/com/google/gitiles/VisibilityCache.java
index 3a700d3..e90d3d1 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/VisibilityCache.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/VisibilityCache.java
@@ -16,14 +16,11 @@
 
 import static com.google.common.base.MoreObjects.toStringHelper;
 import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.common.base.Predicates.not;
 import static com.google.common.collect.Collections2.filter;
 import static java.util.Objects.hash;
 import static org.eclipse.jgit.lib.Constants.R_HEADS;
 import static org.eclipse.jgit.lib.Constants.R_TAGS;
 
-import com.google.common.base.Predicate;
-import com.google.common.base.Predicates;
 import com.google.common.base.Throwables;
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
@@ -160,25 +157,19 @@
     // close to a head. Tags tend to be much further back in history and just
     // clutter up the priority queue in the common case.
     return isReachableFrom(walk, commit, knownReachable)
-        || isReachableFromRefs(walk, commit, filter(allRefs, refStartsWith(R_HEADS)))
-        || isReachableFromRefs(walk, commit, filter(allRefs, refStartsWith(R_TAGS)))
-        || isReachableFromRefs(walk, commit, filter(allRefs, otherRefs()));
+        || isReachableFromRefs(walk, commit, filter(allRefs, r -> refStartsWith(r, R_HEADS)))
+        || isReachableFromRefs(walk, commit, filter(allRefs, r -> refStartsWith(r, R_TAGS)))
+        || isReachableFromRefs(walk, commit, filter(allRefs, r -> otherRefs(r)));
   }
 
-  private static Predicate<Ref> refStartsWith(final String prefix) {
-    return new Predicate<Ref>() {
-      @Override
-      public boolean apply(Ref ref) {
-        return ref.getName().startsWith(prefix);
-      }
-    };
+  private static boolean refStartsWith(Ref ref, String prefix) {
+    return ref.getName().startsWith(prefix);
   }
 
-  @SuppressWarnings("unchecked")
-  private static Predicate<Ref> otherRefs() {
-    return not(
-        Predicates.<Ref>or(
-            refStartsWith(R_HEADS), refStartsWith(R_TAGS), refStartsWith("refs/changes/")));
+  private static boolean otherRefs(Ref r) {
+    return !(refStartsWith(r, R_HEADS)
+        || refStartsWith(r, R_TAGS)
+        || refStartsWith(r, "refs/changes/"));
   }
 
   private boolean isReachableFromRefs(RevWalk walk, RevCommit commit, Collection<Ref> refs)