Renderer: Use native Function from Java 8 instead of Guava

And convert callers to use Stream API rather than FluentIterable.

Change-Id: I4fe140b0ddd240b4c328c2393d975ec6203b0007

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

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/DebugRenderer.java b/gitiles-servlet/src/main/java/com/google/gitiles/DebugRenderer.java
index 5ec22f2..791067b 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/DebugRenderer.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/DebugRenderer.java
@@ -15,9 +15,10 @@
 package com.google.gitiles;
 
 import static com.google.common.base.Preconditions.checkState;
+import static java.util.stream.Collectors.toList;
 
-import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Streams;
 import com.google.common.hash.HashCode;
 import com.google.template.soy.SoyFileSet;
 import com.google.template.soy.tofu.SoyTofu;
@@ -36,7 +37,7 @@
         fileUrlMapper(soyTemplatesRoot + File.separator),
         ImmutableMap.<String, String>of(),
         staticPrefix,
-        FluentIterable.from(customTemplatesFilenames).transform(fileUrlMapper()),
+        Streams.stream(customTemplatesFilenames).map(fileUrlMapper()).collect(toList()),
         siteTitle);
   }
 

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

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
index 3e8867d..b815f12 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
@@ -19,9 +19,9 @@
 import static com.google.common.base.Preconditions.checkState;
 import static com.google.gitiles.GitilesServlet.STATIC_PREFIX;
 import static com.google.gitiles.Renderer.fileUrlMapper;
+import static java.util.stream.Collectors.toList;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.LinkedListMultimap;
 import com.google.common.collect.ListMultimap;
@@ -317,9 +317,9 @@
       renderer =
           new DefaultRenderer(
               filterConfig.getServletContext().getContextPath() + STATIC_PREFIX,
-              FluentIterable.from(
-                      Arrays.asList(config.getStringList("gitiles", null, "customTemplates")))
-                  .transform(fileUrlMapper()),
+              Arrays.stream(config.getStringList("gitiles", null, "customTemplates"))
+                  .map(fileUrlMapper())
+                  .collect(toList()),
               firstNonNull(config.getString("gitiles", null, "siteTitle"), "Gitiles"));
     }
   }

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

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/Renderer.java b/gitiles-servlet/src/main/java/com/google/gitiles/Renderer.java
index 86a4a9c..d4c2872 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/Renderer.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/Renderer.java
@@ -19,7 +19,6 @@
 import static com.google.common.base.Preconditions.checkState;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.MapMaker;
@@ -39,6 +38,7 @@
 import java.net.URL;
 import java.util.Map;
 import java.util.concurrent.ConcurrentMap;
+import java.util.function.Function;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;