Remaining changes to build all code in src.git with -Wimplicit-fallthrough.

This CL was uploaded by git cl split.

R=vabr@chromium.org

Bug: 177475
Change-Id: I9f5deffdff32fbb2b733a3d3b8110638bac04bbb
Reviewed-on: https://chromium-review.googlesource.com/891779Reviewed-by: Vaclav Brozek <vabr@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532818}

components/autofill/content/renderer/page_passwords_analyser.cc

@@ -320,7 +320,7 @@ void GuessAutocompleteAttributesForPasswordFields(
   switch (password_count) {
     case 3:
       (*autocomplete_suggestions)[password_inputs[0]] = "current-password";
-    // Fall-through here to match the last two password fields.
+      FALLTHROUGH;  // To match the last two password fields.
     case 2:
       (*autocomplete_suggestions)[password_inputs[password_count - 2]] =
           "new-password";