Add presubmit check for the deprecated MessageLoopProxy class

BUG=465354

Review URL: https://codereview.chromium.org/1097763002

Cr-Commit-Position: refs/heads/master@{#325828}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 0ce83a6..99c0260 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -250,6 +250,15 @@
         r'extensions[\\\/]renderer[\\\/]safe_builtins\.*',
       ),
     ),
+    (
+      'MessageLoopProxy',
+      (
+        'MessageLoopProxy is deprecated. ',
+        'Please use SingleThreadTaskRunner or ThreadTaskRunnerHandle instead.'
+      ),
+      True,
+      (),
+    ),
 )
 
 _IPC_ENUM_TRAITS_DEPRECATED = (