Upgrade Guava to 22.0

Hashing.sha1() is deprecated. Replace it with murmur3_128.

See the release notes for a full list of changes in this version.

https://github.com/google/guava/wiki/Release22

Change-Id: Iefc239ddc24f4773927c449252fca607d6fe7530
diff --git a/WORKSPACE b/WORKSPACE
index 0b17e1a..ebfb757 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -28,8 +28,8 @@
 
 maven_jar(
     name = "guava",
-    artifact = "com.google.guava:guava:21.0",
-    sha1 = "3a3d111be1be1b745edfa7d91678a12d7ed38709",
+    artifact = "com.google.guava:guava:22.0",
+    sha1 = "3564ef3803de51fb0530a8377ec6100b33b0d073",
 )
 
 maven_jar(
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 d4c2872..efeef9c 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/Renderer.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/Renderer.java
@@ -134,7 +134,7 @@
     URL u = templates.get(soyFile);
     checkState(u != null, "Missing Soy template %s", soyFile);
 
-    Hasher h = Hashing.sha1().newHasher();
+    Hasher h = Hashing.murmur3_128().newHasher();
     try (InputStream is = u.openStream();
         OutputStream os = Funnels.asOutputStream(h)) {
       ByteStreams.copy(is, os);
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/doc/DocServlet.java b/gitiles-servlet/src/main/java/com/google/gitiles/doc/DocServlet.java
index 0f83cce..3c7f54a 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/doc/DocServlet.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/doc/DocServlet.java
@@ -139,7 +139,7 @@
 
   private String etag(MarkdownFile srcmd, @Nullable MarkdownFile navmd) {
     byte[] b = new byte[Constants.OBJECT_ID_LENGTH];
-    Hasher h = Hashing.sha1().newHasher();
+    Hasher h = Hashing.murmur3_128().newHasher();
     h.putInt(ETAG_GEN);
 
     renderer.getTemplateHash(SOY_FILE).writeBytesTo(b, 0, b.length);