Convert some usages of Function to lambda Change-Id: Ifeccf4a117527edb4c2be28b3b9205d153a6cdd7

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 4e917c4..f066d40 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.Function;
 import com.google.common.base.Predicate;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableSet;
@@ -204,14 +203,7 @@
                 }
               })
           .toSortedList(
-              Ordering.natural()
-                  .onResultOf(
-                      new Function<Ref, String>() {
-                        @Override
-                        public String apply(Ref ref) {
-                          return ref.getName();
-                        }
-                      }));
+              Ordering.natural().onResultOf(r -> r.getName()));
     }
 
     private AbstractTreeIterator getTreeIterator(RevCommit commit) throws IOException {

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/RefServlet.java b/gitiles-servlet/src/main/java/com/google/gitiles/RefServlet.java
index 5aa4119..d40962b 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/RefServlet.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/RefServlet.java

@@ -17,7 +17,6 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
@@ -139,19 +138,17 @@
         limit);
   }
 
-  private static Ordering<Ref> tagComparator(final TimeCache timeCache, final RevWalk walk) {
+  private static Long getTime(RevWalk walk, TimeCache timeCache, Ref ref) {
+    try {
+      return timeCache.getTime(walk, ref.getObjectId());
+    } catch (IOException e) {
+      throw new UncheckedExecutionException(e);
+    }
+  }
+
+  private static Ordering<Ref> tagComparator(TimeCache timeCache, RevWalk walk) {
     return Ordering.natural()
-        .onResultOf(
-            new Function<Ref, Long>() {
-              @Override
-              public Long apply(Ref ref) {
-                try {
-                  return timeCache.getTime(walk, ref.getObjectId());
-                } catch (IOException e) {
-                  throw new UncheckedExecutionException(e);
-                }
-              }
-            })
+        .onResultOf((Ref r) -> getTime(walk, timeCache, r))
         .reverse()
         .compound(RefComparator.INSTANCE);
   }

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 657bba8..3a700d3 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/VisibilityCache.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/VisibilityCache.java

@@ -22,7 +22,6 @@
 import static org.eclipse.jgit.lib.Constants.R_HEADS;
 import static org.eclipse.jgit.lib.Constants.R_TAGS;
 
-import com.google.common.base.Function;
 import com.google.common.base.Predicate;
 import com.google.common.base.Predicates;
 import com.google.common.base.Throwables;
@@ -189,15 +188,7 @@
         commit,
         Collections2.transform(
             refs,
-            new Function<Ref, ObjectId>() {
-              @Override
-              public ObjectId apply(Ref ref) {
-                if (ref.getPeeledObjectId() != null) {
-                  return ref.getPeeledObjectId();
-                }
-                return ref.getObjectId();
-              }
-            }));
+            r -> r.getPeeledObjectId() != null ? r.getPeeledObjectId() : r.getObjectId()));
   }
 
   private boolean isReachableFrom(RevWalk walk, RevCommit commit, Collection<ObjectId> ids)

diff --git a/gitiles-servlet/src/test/java/com/google/gitiles/FakeHttpServletRequest.java b/gitiles-servlet/src/test/java/com/google/gitiles/FakeHttpServletRequest.java
index 51cb9ae..ba94c3e 100644
--- a/gitiles-servlet/src/test/java/com/google/gitiles/FakeHttpServletRequest.java
+++ b/gitiles-servlet/src/test/java/com/google/gitiles/FakeHttpServletRequest.java

@@ -19,7 +19,6 @@
 import static com.google.gitiles.TestGitilesUrls.URLS;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
-import com.google.common.base.Function;
 import com.google.common.base.Splitter;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.LinkedListMultimap;
@@ -141,18 +140,14 @@
     return Iterables.getFirst(parameters.get(name), null);
   }
 
-  private static final Function<Collection<String>, String[]> STRING_COLLECTION_TO_ARRAY =
-      new Function<Collection<String>, String[]>() {
-        @Override
-        public String[] apply(Collection<String> values) {
-          return values.toArray(new String[0]);
-        }
-      };
+  private static final String[] stringCollectionToArray(Collection<String> values) {
+    return values.toArray(new String[0]);
+  }
 
   @Override
   public Map<String, String[]> getParameterMap() {
     return Collections.unmodifiableMap(
-        Maps.transformValues(parameters.asMap(), STRING_COLLECTION_TO_ARRAY));
+        Maps.transformValues(parameters.asMap(), c -> stringCollectionToArray(c)));
   }
 
   @Override
@@ -162,7 +157,7 @@
 
   @Override
   public String[] getParameterValues(String name) {
-    return STRING_COLLECTION_TO_ARRAY.apply(parameters.get(name));
+    return stringCollectionToArray(parameters.get(name));
   }
 
   public void setQueryString(String qs) {