Replace one more function with lambda

Change-Id: I87f5ad2c06b1f37b0f70fe0ed86b309556ac8a78

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

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/DefaultRenderer.java b/gitiles-servlet/src/main/java/com/google/gitiles/DefaultRenderer.java
index 0d78e24..c43c7a8 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/DefaultRenderer.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/DefaultRenderer.java
@@ -14,12 +14,12 @@
 
 package com.google.gitiles;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.io.Resources;
 import com.google.template.soy.SoyFileSet;
 import com.google.template.soy.tofu.SoyTofu;
+
 import java.net.URL;
 import java.util.Map;
 
@@ -41,12 +41,7 @@
       Iterable<URL> customTemplates,
       String siteTitle) {
     super(
-        new Function<String, URL>() {
-          @Override
-          public URL apply(String name) {
-            return Resources.getResource(Renderer.class, "templates/" + name);
-          }
-        },
+        r -> Resources.getResource(Renderer.class, "templates/" + r),
         globals,
         staticPrefix,
         customTemplates,