diff --git a/tools/api_sample_coverage.py b/tools/api_sample_coverage.py
index 2d9b0d2..448a0be 100755
--- a/tools/api_sample_coverage.py
+++ b/tools/api_sample_coverage.py
@@ -2,7 +2,6 @@
 # Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
-
 '''
 Compare the R8 API used by the API usage sample to the API kept by @Keep.
 '''
@@ -21,57 +20,67 @@
 
 
 def main(output_dir=None):
-  if output_dir is None:
-    output_dir = ''
+    if output_dir is None:
+        output_dir = ''
 
-  javaExecutable = jdk.GetJavaExecutable()
-  printseeds_path = os.path.join(output_dir, 'keep-seeds.txt')
-  printseeds_args = [
-    javaExecutable, '-jar', utils.R8_JAR, 'printseeds',
-    utils.RT_JAR, utils.R8_JAR, utils.R8LIB_KEEP_RULES,
-  ]
-  write_sorted_lines(printseeds_args, printseeds_path)
+    javaExecutable = jdk.GetJavaExecutable()
+    printseeds_path = os.path.join(output_dir, 'keep-seeds.txt')
+    printseeds_args = [
+        javaExecutable,
+        '-jar',
+        utils.R8_JAR,
+        'printseeds',
+        utils.RT_JAR,
+        utils.R8_JAR,
+        utils.R8LIB_KEEP_RULES,
+    ]
+    write_sorted_lines(printseeds_args, printseeds_path)
 
-  printuses_path = os.path.join(output_dir, 'sample-uses.txt')
-  printuses_args = [
-    javaExecutable, '-jar', utils.R8_JAR, 'printuses',
-    utils.RT_JAR, utils.R8_JAR, API_SAMPLE_JAR,
-  ]
-  write_sorted_lines(printuses_args, printuses_path)
+    printuses_path = os.path.join(output_dir, 'sample-uses.txt')
+    printuses_args = [
+        javaExecutable,
+        '-jar',
+        utils.R8_JAR,
+        'printuses',
+        utils.RT_JAR,
+        utils.R8_JAR,
+        API_SAMPLE_JAR,
+    ]
+    write_sorted_lines(printuses_args, printuses_path)
 
-  print_diff(printseeds_path, printuses_path)
+    print_diff(printseeds_path, printuses_path)
 
 
 def write_sorted_lines(cmd_args, output_path):
-  utils.PrintCmd(cmd_args)
-  output_lines = subprocess.check_output(cmd_args).splitlines(True)
-  print("Write output to %s" % output_path)
-  output_lines.sort()
-  with open(output_path, 'w') as fp:
-    for line in output_lines:
-      fp.write(line)
+    utils.PrintCmd(cmd_args)
+    output_lines = subprocess.check_output(cmd_args).splitlines(True)
+    print("Write output to %s" % output_path)
+    output_lines.sort()
+    with open(output_path, 'w') as fp:
+        for line in output_lines:
+            fp.write(line)
 
 
 def print_diff(printseeds_path, printuses_path):
-  with open(printseeds_path) as fp:
-    seeds = set(fp.read().splitlines())
-  with open(printuses_path) as fp:
-    uses = set(fp.read().splitlines())
-  only_in_seeds = seeds - uses
-  only_in_uses = uses - seeds
-  if only_in_seeds:
-    print("%s lines with '-' are marked @Keep " % len(only_in_seeds) +
-          "but not used by sample.")
-  if only_in_uses:
-    print("%s lines with '+' are used by sample " % len(only_in_uses) +
-          "but are missing @Keep annotations.")
-  for line in sorted(only_in_seeds):
-    print('-' + line)
-  for line in sorted(only_in_uses):
-    print('+' + line)
-  if not only_in_seeds and not only_in_uses:
-    print('Sample uses the entire set of members marked @Keep. Well done!')
+    with open(printseeds_path) as fp:
+        seeds = set(fp.read().splitlines())
+    with open(printuses_path) as fp:
+        uses = set(fp.read().splitlines())
+    only_in_seeds = seeds - uses
+    only_in_uses = uses - seeds
+    if only_in_seeds:
+        print("%s lines with '-' are marked @Keep " % len(only_in_seeds) +
+              "but not used by sample.")
+    if only_in_uses:
+        print("%s lines with '+' are used by sample " % len(only_in_uses) +
+              "but are missing @Keep annotations.")
+    for line in sorted(only_in_seeds):
+        print('-' + line)
+    for line in sorted(only_in_uses):
+        print('+' + line)
+    if not only_in_seeds and not only_in_uses:
+        print('Sample uses the entire set of members marked @Keep. Well done!')
 
 
 if __name__ == '__main__':
-  main(**vars(parser.parse_args()))
+    main(**vars(parser.parse_args()))