Fix code coverage.
diff --git a/tools/dockerfile/test/multilang_jessie_x64/Dockerfile b/tools/dockerfile/test/multilang_jessie_x64/Dockerfile
new file mode 100644
index 0000000..71ebf2b
--- /dev/null
+++ b/tools/dockerfile/test/multilang_jessie_x64/Dockerfile
@@ -0,0 +1,155 @@
+# Copyright 2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+FROM debian:jessie
+
+# Install Git and basic packages.
+RUN apt-get update && apt-get install -y \
+  autoconf \
+  autotools-dev \
+  build-essential \
+  bzip2 \
+  ccache \
+  curl \
+  gcc \
+  gcc-multilib \
+  git \
+  golang \
+  gyp \
+  lcov \
+  libc6 \
+  libc6-dbg \
+  libc6-dev \
+  libgtest-dev \
+  libtool \
+  make \
+  perl \
+  strace \
+  python-dev \
+  python-setuptools \
+  python-yaml \
+  telnet \
+  unzip \
+  wget \
+  zip && apt-get clean
+
+#================
+# Build profiling
+RUN apt-get update && apt-get install -y time && apt-get clean
+
+#================
+# C# dependencies
+
+# Update to a newer version of mono
+RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
+RUN echo "deb http://download.mono-project.com/repo/debian wheezy main" | tee /etc/apt/sources.list.d/mono-xamarin.list
+RUN echo "deb http://download.mono-project.com/repo/debian wheezy-apache24-compat main" | tee -a /etc/apt/sources.list.d/mono-xamarin.list
+RUN echo "deb http://download.mono-project.com/repo/debian wheezy-libjpeg62-compat main" | tee -a /etc/apt/sources.list.d/mono-xamarin.list
+RUN echo "deb http://download.mono-project.com/repo/debian wheezy-libtiff-compat main" | tee -a /etc/apt/sources.list.d/mono-xamarin.list
+
+# Install dependencies
+RUN apt-get update && apt-get -y dist-upgrade && apt-get install -y \
+    mono-devel \
+    ca-certificates-mono \
+    nuget \
+    && apt-get clean
+
+#=================
+# C++ dependencies
+RUN apt-get update && apt-get -y install libgflags-dev libgtest-dev libc++-dev clang && apt-get clean
+
+#==================
+# Node dependencies
+
+# Install nvm
+RUN touch .profile
+RUN curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.25.4/install.sh | bash
+RUN /bin/bash -l -c "nvm install 0.12 && npm config set cache /tmp/npm-cache"
+
+#=================
+# PHP dependencies
+
+# Install dependencies
+
+RUN /bin/bash -l -c "echo 'deb http://packages.dotdeb.org wheezy-php55 all' \
+    >> /etc/apt/sources.list.d/dotdeb.list"
+RUN /bin/bash -l -c "echo 'deb-src http://packages.dotdeb.org wheezy-php55 all' \
+    >> /etc/apt/sources.list.d/dotdeb.list"
+RUN wget http://www.dotdeb.org/dotdeb.gpg -O- | apt-key add -
+
+RUN apt-get update && apt-get install -y \
+    git php5 php5-dev phpunit unzip
+
+#==================
+# Ruby dependencies
+
+# Install rvm
+RUN gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
+RUN \curl -sSL https://get.rvm.io | bash -s stable
+
+# Install Ruby 2.1
+RUN /bin/bash -l -c "rvm install ruby-2.1"
+RUN /bin/bash -l -c "rvm use --default ruby-2.1"
+RUN /bin/bash -l -c "echo 'gem: --no-ri --no-rdoc' > ~/.gemrc"
+RUN /bin/bash -l -c "echo 'export PATH=/usr/local/rvm/bin:$PATH' >> ~/.bashrc"
+RUN /bin/bash -l -c "echo 'rvm --default use ruby-2.1' >> ~/.bashrc"
+RUN /bin/bash -l -c "gem install bundler --no-ri --no-rdoc"
+
+#====================
+# Python dependencies
+
+# Install dependencies
+
+RUN apt-get update && apt-get install -y \
+    python-all-dev \
+    python3-all-dev \
+    python-pip
+
+# Install Python packages from PyPI
+RUN pip install pip --upgrade
+RUN pip install virtualenv
+RUN pip install futures==2.2.0 enum34==1.0.4 protobuf==3.0.0a2 tox
+
+# Prepare ccache
+RUN ln -s /usr/bin/ccache /usr/local/bin/gcc
+RUN ln -s /usr/bin/ccache /usr/local/bin/g++
+RUN ln -s /usr/bin/ccache /usr/local/bin/cc
+RUN ln -s /usr/bin/ccache /usr/local/bin/c++
+RUN ln -s /usr/bin/ccache /usr/local/bin/clang
+RUN ln -s /usr/bin/ccache /usr/local/bin/clang++
+
+#======================
+# Zookeeper dependencies
+# TODO(jtattermusch): is zookeeper still needed?
+RUN apt-get install -y libzookeeper-mt-dev
+
+RUN mkdir /var/local/jenkins
+
+# Define the default command.
+CMD ["bash"]