Revert "git-cl: Fix format --dry-run not working with --full."

This reverts commit fc132e61dbe484619d780ce9dedb08986a090706.

Reason for revert: Causes all presubmit checks to return dirty
format because of a non-zero diff output.

Original change's description:
> git-cl: Fix format --dry-run not working with --full.
> 
> The --full option would skip setting the return value of the format
> command when used with --dry-run. This in turn would cause the
> presubmit check to always pass when --full was enabled in a repo by
> default.
> 
> Was discovered in the ANGLE repository.
> 
> Bug: angleproject:4241
> Change-Id: Ie6cb423a6818c1e26781d77938a0dd22c02b4c16
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1987835
> Commit-Queue: Jamie Madill <jmadill@chromium.org>
> Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
> Auto-Submit: Jamie Madill <jmadill@chromium.org>

TBR=ehmaldonado@chromium.org,jmadill@chromium.org

Change-Id: I0a4c51117ab20606f6dbb1f7a3ba40f87da1e939
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: angleproject:4241
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1993907
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/tests/git_cl_test.py b/tests/git_cl_test.py
index f4d20ac..e3f6f57 100755
--- a/tests/git_cl_test.py
+++ b/tests/git_cl_test.py
@@ -32,7 +32,6 @@
 # We have to disable monitoring before importing git_cl.
 metrics.DISABLE_METRICS_COLLECTION = True
 
-import clang_format
 import gerrit_util
 import git_cl
 import git_common
@@ -3442,52 +3441,20 @@
 
   def setUp(self):
     super(CMDFormatTestCase, self).setUp()
-    mock.patch('git_cl.RunCommand').start()
-    mock.patch('clang_format.FindClangFormatToolInChromiumTree').start()
-    mock.patch('clang_format.FindClangFormatScriptInChromiumTree').start()
-    mock.patch('git_cl.settings').start()
     self._top_dir = tempfile.mkdtemp()
-    self.addCleanup(mock.patch.stopall)
 
   def tearDown(self):
     shutil.rmtree(self._top_dir)
     super(CMDFormatTestCase, self).tearDown()
 
-  def _make_temp_file(self, fname, contents):
-    with open(os.path.join(self._top_dir, fname), 'w') as tf:
-      tf.write('\n'.join(contents))
-
   def _make_yapfignore(self, contents):
-    self._make_temp_file('.yapfignore', contents)
+    with open(os.path.join(self._top_dir, '.yapfignore'), 'w') as yapfignore:
+      yapfignore.write('\n'.join(contents))
 
   def _check_yapf_filtering(self, files, expected):
     self.assertEqual(expected, git_cl._FilterYapfIgnoredFiles(
         files, git_cl._GetYapfIgnorePatterns(self._top_dir)))
 
-  def testClangFormatDiff(self):
-    git_cl.RunCommand.return_value = 'error'
-    git_cl.settings.GetFormatFullByDefault.return_value = False
-    return_value = git_cl._RunClangFormatDiff(
-        mock.Mock(full=True, dry_run=True, diff=False), ['.'], self._top_dir,
-        'HEAD')
-    self.assertEqual(2, return_value)
-    return_value = git_cl._RunClangFormatDiff(
-        mock.Mock(full=False, dry_run=True, diff=False), ['.'], self._top_dir,
-        'HEAD')
-    self.assertEqual(2, return_value)
-
-  def testClangFormatNoDiff(self):
-    git_cl.RunCommand.return_value = ''
-    git_cl.settings.GetFormatFullByDefault.return_value = False
-    return_value = git_cl._RunClangFormatDiff(
-        mock.Mock(full=True, dry_run=True, diff=False), ['.'], self._top_dir,
-        'HEAD')
-    self.assertEqual(0, return_value)
-    return_value = git_cl._RunClangFormatDiff(
-        mock.Mock(full=False, dry_run=True, diff=False), ['.'], self._top_dir,
-        'HEAD')
-    self.assertEqual(0, return_value)
-
   def testYapfignoreExplicit(self):
     self._make_yapfignore(['foo/bar.py', 'foo/bar/baz.py'])
     files = [