Remove all references to Xvfb

Xvfb isn't needed anymore for running the Gerrit UI tests
and therefore can be eliminated altogether.

It would not just make the builds slightly faster but also
reduce the size of the Docker image by avoiding the installation
of the entire X subsystem.

Change-Id: I711480a68108f6137356c448fd0c9f3681cf7a47
diff --git a/jenkins-docker/master/Dockerfile b/jenkins-docker/master/Dockerfile
index ab280a3..7b11abe 100644
--- a/jenkins-docker/master/Dockerfile
+++ b/jenkins-docker/master/Dockerfile
@@ -50,7 +50,6 @@
 COPY config.xml $JENKINS_REF
 COPY jenkins.plugins.logstash.LogstashInstallation.xml $JENKINS_REF
 COPY jenkins.model.JenkinsLocationConfiguration.xml $JENKINS_REF
-COPY org.jenkinsci.plugins.xvfb.Xvfb.xml $JENKINS_REF
 
 RUN mkdir -p $JENKINS_REF/.ssh && \
     chown -R jenkins:jenkins $JENKINS_REF/.ssh && \
diff --git a/jenkins-docker/master/org.jenkinsci.plugins.xvfb.Xvfb.xml b/jenkins-docker/master/org.jenkinsci.plugins.xvfb.Xvfb.xml
deleted file mode 100644
index 20285ad..0000000
--- a/jenkins-docker/master/org.jenkinsci.plugins.xvfb.Xvfb.xml
+++ /dev/null
@@ -1,10 +0,0 @@
-<?xml version='1.0' encoding='UTF-8'?>
-<org.jenkinsci.plugins.xvfb.Xvfb_-XvfbBuildWrapperDescriptor plugin="xvfb@1.1.3">
-  <installations>
-    <org.jenkinsci.plugins.xvfb.XvfbInstallation>
-      <name>Xvfb</name>
-      <home>/usr/bin</home>
-      <properties/>
-    </org.jenkinsci.plugins.xvfb.XvfbInstallation>
-  </installations>
-</org.jenkinsci.plugins.xvfb.Xvfb_-XvfbBuildWrapperDescriptor>
\ No newline at end of file
diff --git a/jenkins-docker/master/plugins.txt b/jenkins-docker/master/plugins.txt
index e955275..abaca17 100644
--- a/jenkins-docker/master/plugins.txt
+++ b/jenkins-docker/master/plugins.txt
@@ -95,4 +95,3 @@
 workflow-scm-step:2.9
 workflow-step-api:2.20
 workflow-support:3.3
-xvfb:1.1.3
diff --git a/jenkins-docker/slave-debian/Dockerfile b/jenkins-docker/slave-debian/Dockerfile
index f9f7974..87580eb 100644
--- a/jenkins-docker/slave-debian/Dockerfile
+++ b/jenkins-docker/slave-debian/Dockerfile
@@ -13,7 +13,6 @@
 RUN apt-get update && apt-get install -y \
     openssh-server \
     curl \
-    xvfb \
     python-dev \
     python-pip \
     python-yaml \
diff --git a/jenkins/gerrit-bazel-template.yaml b/jenkins/gerrit-bazel-template.yaml
index 769a08f..cd82282 100644
--- a/jenkins/gerrit-bazel-template.yaml
+++ b/jenkins/gerrit-bazel-template.yaml
@@ -30,15 +30,6 @@
           type: absolute
           fail: false
       - timestamps
-      - xvfb:
-          installation-name: Xvfb
-          display-name: 1
-          parallel-build: false
-          timeout: 30
-          screen: 1024x768x16
-          additional-options: -fbdir /tmp
-          debug: true
-          shutdown-with-build: false
       - credentials-binding:
           - username-password-separated:
               credential-id: gerrit.googlesource.com