diff --git a/DEPS b/DEPS
index 30a5158..0ac437c 100644
--- a/DEPS
+++ b/DEPS
@@ -37,6 +37,12 @@
                 "webrtc.DEPS"],
   },
   {
+    "pattern": ".",
+    "action" : ["python",
+                "webrtc.DEPS/download_node.py",
+                "webrtc.DEPS"],
+  },
+  {
     # "Build" AppRTC, i.e. move it to the out/ dir where the browser test
     # can find it. This is only done on runhooks.
     "pattern": ".",
@@ -56,6 +62,12 @@
                 "webrtc.DEPS/build_apprtc_collider.py"],
   },
   {
+    # Build AppRTC closure Javascript.
+    "pattern": ".",
+    "action" : ["python",
+                "webrtc.DEPS/build_apprtc_closure.py"],
+  },
+  {
     # Download media files and tools used by the webrtc quality browser tests,
     # chrome/browser/media/chrome_webrtc_audio_quality_browsertest.cc and
     # chrome/browser/media/chrome_webrtc_video_quality_browsertest.cc.
diff --git a/build_apprtc_closure.py b/build_apprtc_closure.py
new file mode 100755
index 0000000..60703cf
--- /dev/null
+++ b/build_apprtc_closure.py
@@ -0,0 +1,48 @@
+#!/usr/bin/python
+# Copyright 2015 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.
+
+"""Invokes the AppRTC closure compiler.
+
+The AppRTC javascript code must be closure-compiled. This script uses
+the node toolchain we downloaded earlier.
+"""
+
+import os
+import shutil
+import subprocess
+import sys
+
+import utils
+
+
+def main():
+  node_path = os.path.abspath('node')
+  if not os.path.exists(node_path):
+    return 'Expected node at %s.' % node_path
+  samples_path = os.path.join('src', 'out', 'webrtc-samples')
+  if not os.path.exists(samples_path):
+    return 'Expected webrtc-samples at %s.' % os.path.abspath(samples_path)
+
+  os.chdir(samples_path)
+  
+  if utils.GetPlatform() is 'win':
+    npm_bin = os.path.join(node_path, 'npm.cmd')
+    node_bin = os.path.join(node_path, 'node.exe')
+  else:
+    npm_bin = os.path.join(node_path, 'bin', 'npm')
+    node_bin = os.path.join(node_path, 'bin', 'node')
+
+  subprocess.check_call([npm_bin, 'install'])
+  local_grunt_bin = os.path.join('node_modules', 'grunt-cli', 'bin', 'grunt')
+
+  if not os.path.exists(local_grunt_bin):
+    return ('Missing grunt-cli in the webrtc-samples checkout; did '
+            'npm install fail?')
+
+  subprocess.check_call([node_bin, local_grunt_bin, 'closurecompiler:debug'])
+
+
+if __name__ == '__main__':
+  sys.exit(main())
diff --git a/copy_apprtc.py b/copy_apprtc.py
index c091aa6..5a9a3c9 100755
--- a/copy_apprtc.py
+++ b/copy_apprtc.py
@@ -10,13 +10,25 @@
 understand those symlinks).
 """
 
+import os
 import shutil
 
+import utils
 
 if __name__ == '__main__':
-  web_samples_dir = 'webrtc-samples/samples/web'
-  shutil.rmtree('src/out/apprtc', ignore_errors=True)
-  shutil.copytree(web_samples_dir + '/content/apprtc',
-                  'src/out/apprtc', ignore=shutil.ignore_patterns('.svn'))
-  shutil.copyfile(web_samples_dir + '/js/adapter.js',
-		  'src/out/apprtc/js/adapter.js')
+  target_dir = os.path.join('src', 'out', 'webrtc-samples')
+  if utils.GetPlatform() is 'win':
+    # Work around the fact that node_modules create ridiculously long paths.
+    # Unfortunately shutil will choke on those on Windows, but not rmdir.
+    os.system('rmdir /s /q %s' % target_dir)
+  else:
+    shutil.rmtree(target_dir, ignore_errors=True)
+  shutil.copytree('webrtc-samples',
+                  target_dir, ignore=shutil.ignore_patterns('.svn', '.git'))
+  apprtc_subdir = os.path.join('samples', 'web', 'content', 'apprtc')
+
+  # This file is symlinked on windows, so copy it since win doesn't understand
+  # symlinks.
+  shutil.copyfile(os.path.join('webrtc-samples', 'samples', 'web',
+                               'js', 'adapter.js'),
+                  os.path.join(target_dir, apprtc_subdir, 'js', 'adapter.js'))
diff --git a/download_golang.py b/download_golang.py
index c61ba00..ce7573e 100755
--- a/download_golang.py
+++ b/download_golang.py
@@ -19,18 +19,6 @@
 import utils
 
 
-def _DownloadFilesFromGoogleStorage(webrtc_deps_path):
-  print 'Downloading files in %s...' % webrtc_deps_path
-
-  extension = 'bat' if 'win32' in sys.platform else 'py'
-  cmd = ['download_from_google_storage.%s' % extension,
-         '--bucket=chromium-webrtc-resources',
-         '--auto_platform',
-         '--recursive',
-         '--directory', webrtc_deps_path]
-  subprocess.check_call(cmd)
-
-
 def _GetGoArchivePathForPlatform():
   archive_extension = 'zip' if utils.GetPlatform() == 'win' else 'tar.gz'
   return os.path.join(utils.GetPlatform(), 'go.%s' % archive_extension)
@@ -47,9 +35,10 @@
   archive_path = os.path.join(golang_path, _GetGoArchivePathForPlatform())
   old_archive_sha1 = utils.ComputeSHA1(archive_path)
 
-  _DownloadFilesFromGoogleStorage(golang_path)
+  utils.DownloadFilesFromGoogleStorage(golang_path)
 
-  if old_archive_sha1 != utils.ComputeSHA1(archive_path):
+  if (old_archive_sha1 != utils.ComputeSHA1(archive_path)
+      or not os.path.exists('go')):
     utils.DeleteDirNextToGclient('go')
     utils.UnpackToWorkingDir(archive_path)
 
diff --git a/download_node.py b/download_node.py
new file mode 100755
index 0000000..8d8d82c
--- /dev/null
+++ b/download_node.py
@@ -0,0 +1,55 @@
+#!/usr/bin/python
+# Copyright 2015 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.
+
+"""Downloads the node binaries from WebRTC storage and unpacks it.
+
+Requires that depot_tools is installed and in the PATH. This script expects
+to run with Chrome's base dir as the working directory, e.g. where the .gclient
+file is. This is what should happen if this script is invoked as a hook action.
+"""
+
+import glob
+import os
+import sys
+import tarfile
+import zipfile
+
+import utils
+
+
+def _GetNodeArchivePathForPlatform():
+  archive_extension = 'zip' if utils.GetPlatform() == 'win' else 'tar.gz'
+  return os.path.join(utils.GetPlatform(), 'node.%s' % archive_extension)
+
+
+def _StripVersionNumberFromNodeDir():
+  # The node dir will be called node-x-x-x.tar.gz, rename to just node.
+  unpacked_name = glob.glob('node*')
+  assert len(unpacked_name) == 1, 'Should have precisely one node!'
+  os.rename(unpacked_name[0], 'node')
+
+
+def main(argv):
+  if len(argv) == 1:
+    return 'Usage: %s <path to webrtc.DEPS>' % argv[0]
+  if not os.path.exists('.gclient'):
+    return 'Invoked from wrong dir; invoke from dir with .gclient'
+
+  webrtc_deps_path = argv[1]
+  node_path = os.path.join(webrtc_deps_path, 'node')
+  archive_path = os.path.join(node_path, _GetNodeArchivePathForPlatform())
+  old_archive_sha1 = utils.ComputeSHA1(archive_path)
+
+  utils.DownloadFilesFromGoogleStorage(node_path)
+
+  if (old_archive_sha1 != utils.ComputeSHA1(archive_path)
+      or not os.path.exists('node')):
+    utils.DeleteDirNextToGclient('node')
+    utils.UnpackToWorkingDir(archive_path)
+    _StripVersionNumberFromNodeDir()
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
diff --git a/node/linux/node.tar.gz.sha1 b/node/linux/node.tar.gz.sha1
new file mode 100644
index 0000000..5706dea
--- /dev/null
+++ b/node/linux/node.tar.gz.sha1
@@ -0,0 +1 @@
+3a202a749492e48542d2c28220e43ef6dae084bc
\ No newline at end of file
diff --git a/node/mac/node.tar.gz.sha1 b/node/mac/node.tar.gz.sha1
new file mode 100644
index 0000000..ed7bec7
--- /dev/null
+++ b/node/mac/node.tar.gz.sha1
@@ -0,0 +1 @@
+98f61cb09685ed45f2db6e0fc5ccbdd273204091
\ No newline at end of file
diff --git a/node/win/README b/node/win/README
new file mode 100644
index 0000000..640dab1
--- /dev/null
+++ b/node/win/README
@@ -0,0 +1,9 @@
+This zip file requires some manual work. First, download node.exe
+from http://nodejs.org/download/, then download the npm stuff from
+http://nodejs.org/dist/npm/. Unzip both in the same dir and do this:
+
+mkdir node
+mv node.exe node
+mv npm.cmd node
+mv node_modules node
+zip -r node.zip node
diff --git a/node/win/node.zip.sha1 b/node/win/node.zip.sha1
new file mode 100644
index 0000000..f5bf9e4
--- /dev/null
+++ b/node/win/node.zip.sha1
@@ -0,0 +1 @@
+a0f8d1cf0ef8375f1a760a3c33d6a9f69b045103
\ No newline at end of file
diff --git a/utils.py b/utils.py
index 1cf998d..827cd3e 100755
--- a/utils.py
+++ b/utils.py
@@ -9,10 +9,23 @@
 import os
 import shutil
 import sys
+import subprocess
 import tarfile
 import zipfile
 
 
+def DownloadFilesFromGoogleStorage(path):
+  print 'Downloading files in %s...' % path
+
+  extension = 'bat' if 'win32' in sys.platform else 'py'
+  cmd = ['download_from_google_storage.%s' % extension,
+         '--bucket=chromium-webrtc-resources',
+         '--auto_platform',
+         '--recursive',
+         '--directory', path]
+  subprocess.check_call(cmd)
+
+
 def ComputeSHA1(path):
   if not os.path.exists(path):
     return 0