[ChromeDriver] Update atoms.cc to latest code

Change-Id: I35cddbfae13842633ff611e2f85966ac12e8b6cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1572208Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Tatiana Buldina <buldina@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652872}

third_party/webdriver/README.chromium

@@ -18,7 +18,7 @@ Contents:
   atoms.h, atoms.cc
     These atoms are generated by the webdriver team and are to be checked in
     manually. The current version was generated from revision
-    53f0818fe574877841c331e9647a35985fbfe957.
+    6772bd50767d123a9febe00f2ac2190e06b7e12c.
 
     To generate the atoms using the code found in selenium tree:
       $ git clone https://github.com/SeleniumHQ/selenium.git