Remove Chromium's custom closure runner.

third_party/closure_compiler/roll_closure_compiler

 #!/bin/bash
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 # Download the newest version of Closure Compiler, build it and put into Chrome
 # source tree. Also update externs/chrome_extensions.js.
+#
+# TODO(dbeam): we don't really need to build the compiler any more. We used to
+# need to because we built a custom runner. We could probably just curl
+# https://dl.google.com/closure-compiler/compiler-latest.zip and unzip. And get
+# the externs from rawgit.com.
 
 java -version 2>&1 | head -1 | egrep -q '\b1\.7'
 if [[ $? -ne 0 ]]; then
   echo "This script requires Java 1.7" >&2
   exit 1
 fi
 
 javac -version 2>&1 | egrep -q '\b1\.7'
 if [[ $? -ne 0 ]]; then
   echo "This script requires JDK 1.7" >&2
@@ skipping 42 matching lines @@
 
 echo "Building Closure Compiler"
 mvn install -DskipTests=true --projects com.google.javascript:closure-compiler
 
 if [[ "$?" -ne 0 ]]; then
   echo "Failed to build jar, copying nothing" >&2
   cleanup
   exit 1
 fi
 
-# TODO(dbeam): this .jar seems to be a bit bigger than the jar previously built
-# by ant. I tried many other jars in target/, but none of them were able to
-# build the runner.jar without issue.
+# TODO(dbeam): the Maven-built jar seems a little bigger than the ant version.
 cp target/closure-compiler-1.0-SNAPSHOT.jar "${SCRIPT_DIR}/compiler/compiler.jar"
 
-echo "Re-building runner.jar"
-"${SCRIPT_DIR}/runner/build_runner_jar.py"
-if [[ "$?" -ne 0 ]]; then
-  echo "Failed to build runner.jar, roll unsuccessful"
-  cleanup
-  exit 1
-fi
-
 readonly WARNING="$(cat <<EOT
 //    SSSSSSSSSSSSSSS TTTTTTTTTTTTTTTTTTTTTTT     OOOOOOOOO     PPPPPPPPPPPPPPPPP
 //  SS:::::::::::::::ST:::::::::::::::::::::T   OO:::::::::OO   P::::::::::::::::P
 // S:::::SSSSSS::::::ST:::::::::::::::::::::T OO:::::::::::::OO P::::::PPPPPP:::::P
 // S:::::S     SSSSSSST:::::TT:::::::TT:::::TO:::::::OOO:::::::OPP:::::P     P:::::P
 // S:::::S            TTTTTT  T:::::T  TTTTTTO::::::O   O::::::O  P::::P     P:::::P
 // S:::::S                    T:::::T        O:::::O     O:::::O  P::::P     P:::::P
 //  S::::SSSS                                                     P::::PPPPPP:::::P
 //   SS::::::SSSSS       This file is generated. To update it,    P:::::::::::::PP
 //     SSS::::::::SS          run roll_closure_compiler.          P::::PPPPPPPPP
@@ skipping 47 matching lines @@
 echo "${head_range}"
 if [[ ! -z "${extensions_range}" ]]; then echo "${extensions_range}"; fi
 if [[ ! -z "${polymer_range}" ]]; then echo "${polymer_range}"; fi
 echo
 echo "TBR="
 echo "BUG='"
 echo
 echo "git cl upload"
 
 cleanup