Add ESLint rule for commented out import statements

This is something I've been caught out with a few times when moving code
round, and thought it would be a good ESLint rule. I've enabled the rule
as part of this CL as we currently have few issues that need fixes.

Bug: none
Change-Id: I72c6aad3e4258fbda280e062f98823a068c6bfc8
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/4076326
Reviewed-by: Andres Olivares <[email protected]>
Commit-Queue: Jack Franklin <[email protected]>
diff --git a/.eslintrc.js b/.eslintrc.js
index 047d8a4..a40429e 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// clang-format off
+
 const path = require('path');
 const rulesDirPlugin = require('eslint-plugin-rulesdir');
 rulesDirPlugin.RULES_DIR = path.join(__dirname, 'scripts', 'eslint_rules', 'lib');
@@ -120,6 +122,9 @@
     // Try to spot '// console.log()' left over from debugging
     'rulesdir/commented_out_console': 2,
 
+    // Prevent imports being commented out rather than deleted.
+    'rulesdir/commented_out_import': 2,
+
     // DevTools specific rules
     'rulesdir/es_modules_import': 2,
     'rulesdir/check_license_header': 2,
@@ -180,3 +185,5 @@
     }
   }]
 };
+
+// clang-format on