diff --git a/tools/file_util.py b/tools/file_util.py
index 12e12db09..edc382ba2 100644
--- a/tools/file_util.py
+++ b/tools/file_util.py
@@ -52,7 +52,7 @@ def backup_file(name):
 def copy_file(src, dst, quiet=True):
   """ Copy a file. """
   try:
-    shutil.copy(src, dst)
+    shutil.copy2(src, dst)
     if not quiet:
       sys.stdout.write('Transferring ' + src + ' file.\n')
   except IOError, (errno, strerror):
diff --git a/tools/patch_updater.py b/tools/patch_updater.py
index 0f2efea79..e353ab40b 100644
--- a/tools/patch_updater.py
+++ b/tools/patch_updater.py
@@ -7,19 +7,27 @@ import os
 import re
 import sys
 from exec_util import exec_cmd
+from file_util import copy_file, move_file, read_file, remove_file
 import git_util as git
 
+backup_ext = '.cefbak'
+
 
 def msg(message):
   """ Output a message. """
   sys.stdout.write('--> ' + message + "\n")
 
 
+def linebreak():
+  """ Output a line break. """
+  sys.stdout.write('-' * 80 + "\n")
+
+
 def warn(message):
   """ Output a warning. """
-  sys.stdout.write('-' * 80 + "\n")
+  linebreak()
   sys.stdout.write('!!!! WARNING: ' + message + "\n")
-  sys.stdout.write('-' * 80 + "\n")
+  linebreak()
 
 
 def extract_paths(file):
@@ -67,7 +75,7 @@ parser.add_option(
     action='store_true',
     dest='resave',
     default=False,
-    help='re-save existing patch files to pick up manual changes')
+    help='resave existing patch files to pick up manual changes')
 parser.add_option(
     '--reapply',
     action='store_true',
@@ -80,6 +88,19 @@ parser.add_option(
     dest='revert',
     default=False,
     help='revert all changes from existing patch files')
+parser.add_option(
+    '--backup',
+    action='store_true',
+    dest='backup',
+    default=False,
+    help='backup patched files. Used in combination with --revert.')
+parser.add_option(
+    '--restore',
+    action='store_true',
+    dest='restore',
+    default=False,
+    help='restore backup of patched files that have not changed. If a backup has ' +\
+         'changed the patch file will be resaved. Used in combination with --reapply.')
 parser.add_option(
     '--patch',
     action='extend',
@@ -113,6 +134,8 @@ scope = {}
 execfile(patch_cfg, scope)
 patches = scope["patches"]
 
+failed_patches = {}
+
 # Read each individual patch file.
 patches_dir = os.path.join(patch_dir, 'patches')
 for patch in patches:
@@ -136,6 +159,9 @@ for patch in patches:
     # List of paths added by the patch file.
     added_paths = []
 
+    # True if any backed up files have changed.
+    has_backup_changes = False
+
     if not options.resave:
       if not options.reapply:
         # Revert any changes to existing files in the patch.
@@ -143,6 +169,14 @@ for patch in patches:
           patch_path_abs = os.path.abspath(os.path.join(patch_root_abs, \
                                                         patch_path))
           if os.path.exists(patch_path_abs):
+            if options.backup:
+              backup_path_abs = patch_path_abs + backup_ext
+              if not os.path.exists(backup_path_abs):
+                msg('Creating backup of %s' % patch_path_abs)
+                copy_file(patch_path_abs, backup_path_abs)
+              else:
+                msg('Skipping backup of %s' % patch_path_abs)
+
             msg('Reverting changes to %s' % patch_path_abs)
             cmd = 'git checkout -- %s' % (patch_path_abs)
             result = exec_cmd(cmd, patch_root_abs)
@@ -196,11 +230,34 @@ for patch in patches:
           raise Exception('Failed to apply patch file: %s' % result['err'])
         sys.stdout.write(result['out'])
         if result['out'].find('FAILED') != -1:
+          failed_lines = []
+          for line in result['out'].split('\n'):
+            if line.find('FAILED') != -1:
+              failed_lines.append(line.strip())
           warn('Failed to apply %s, fix manually and run with --resave' % \
                patch['name'])
+          failed_patches[patch['name']] = failed_lines
           continue
 
-    if not options.revert and not options.reapply:
+        if options.restore:
+          # Restore from backup if a backup exists.
+          for patch_path in patch_paths:
+            patch_path_abs = os.path.abspath(os.path.join(patch_root_abs, \
+                                                          patch_path))
+            backup_path_abs = patch_path_abs + backup_ext
+            if os.path.exists(backup_path_abs):
+              if read_file(patch_path_abs) == read_file(backup_path_abs):
+                msg('Restoring backup of %s' % patch_path_abs)
+                remove_file(patch_path_abs)
+                move_file(backup_path_abs, patch_path_abs)
+              else:
+                msg('Discarding backup of %s' % patch_path_abs)
+                remove_file(backup_path_abs)
+                has_backup_changes = True
+            else:
+              msg('No backup of %s' % patch_path_abs)
+
+    if (not options.revert and not options.reapply) or has_backup_changes:
       msg('Saving changes to %s' % patch_file)
       if added_paths:
         # Inform git of the added paths so they appear in the patch file.
@@ -228,3 +285,14 @@ for patch in patches:
       f.close()
   else:
     raise Exception('Patch file does not exist: %s' % patch_file)
+
+if len(failed_patches) > 0:
+  sys.stdout.write("\n")
+  linebreak()
+  sys.stdout.write("!!!! FAILED PATCHES, fix manually and run with --resave\n")
+  for name in sorted(failed_patches.keys()):
+    sys.stdout.write("%s:\n" % name)
+    for line in failed_patches[name]:
+      sys.stdout.write("  %s\n" % line)
+  linebreak()
+  sys.exit(1)