Merge branch 'stable-2.11'

* stable-2.11:
  Use auto-closeable RevWalk
  Remove unused imports
  Avoid NPE when getting groups for anonymous users
  Identify the OAuth provider as simply "GitHub"
  Implementation of Gerrit OAuthServiceProvider

Change-Id: Ie6171cbc237205ba390cae82d15c862fb2d53196
diff --git a/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java b/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java
index 8cf64ab..70eb514 100644
--- a/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java
+++ b/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java
@@ -37,22 +37,6 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-import org.apache.http.HttpResponse;
-import org.apache.http.NameValuePair;
-import org.apache.http.client.HttpClient;
-import org.apache.http.client.entity.UrlEncodedFormEntity;
-import org.apache.http.client.methods.HttpPost;
-import org.apache.http.message.BasicNameValuePair;
-import org.apache.http.util.EntityUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import com.google.common.base.Charsets;
-import com.google.common.base.Strings;
-import com.google.common.io.CharStreams;
-import com.google.gson.Gson;
-import com.google.inject.Inject;
-import com.google.inject.Singleton;
 import com.google.gerrit.extensions.auth.oauth.OAuthToken;
 import com.google.gerrit.extensions.auth.oauth.OAuthVerifier;
 
diff --git a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/GitHubOAuthServiceProvider.java b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/GitHubOAuthServiceProvider.java
index 575ea11..0a617fc 100644
--- a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/GitHubOAuthServiceProvider.java
+++ b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/GitHubOAuthServiceProvider.java
@@ -22,7 +22,6 @@
 import org.slf4j.LoggerFactory;
 
 import com.google.common.collect.Sets;
-import com.google.gerrit.extensions.annotations.PluginName;
 import com.google.gerrit.extensions.auth.oauth.OAuthServiceProvider;
 import com.google.gerrit.extensions.auth.oauth.OAuthToken;
 import com.google.gerrit.extensions.auth.oauth.OAuthUserInfo;
diff --git a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/GuiceHttpModule.java b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/GuiceHttpModule.java
index 625f664..97bc6be 100644
--- a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/GuiceHttpModule.java
+++ b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/GuiceHttpModule.java
@@ -38,9 +38,6 @@
 import com.googlesource.gerrit.plugins.github.velocity.VelocityViewServlet;
 import com.googlesource.gerrit.plugins.github.wizard.VelocityControllerServlet;
 
-import org.apache.http.client.HttpClient;
-import org.apache.velocity.runtime.RuntimeInstance;
-
 public class GuiceHttpModule extends ServletModule {
 
   @Override
diff --git a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/git/PullRequestCreateChange.java b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/git/PullRequestCreateChange.java
index 169f92a..d6a7213 100644
--- a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/git/PullRequestCreateChange.java
+++ b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/git/PullRequestCreateChange.java
@@ -114,8 +114,7 @@
         projectControlFactory.controlFor(project.getNameKey()).controlForRef(
             destinationBranch);
 
-    try {
-      RevWalk revWalk = new RevWalk(git);
+    try (RevWalk revWalk = new RevWalk(git)) {
       try {
         Ref destRef = git.getRef(destinationBranch);
         if (destRef == null) {
@@ -181,7 +180,6 @@
                   doValidation));
         }
       } finally {
-        revWalk.close();
         if (newChange == null) {
           db.rollback();
         }
diff --git a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/wizard/PullRequestListController.java b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/wizard/PullRequestListController.java
index 2d34231..8449edb 100644
--- a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/wizard/PullRequestListController.java
+++ b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/wizard/PullRequestListController.java
@@ -210,10 +210,10 @@
           .listCommits()) {
         ObjectId pullRequestHeadObjectId =
             ObjectId.fromString(pullRequestCommit.getSha());
-
+  
         try {
           gitWalk.parseCommit(pullRequestHeadObjectId);
-
+  
           ResultSet<PatchSet> patchSets;
           try {
             patchSets =