Add string utilities for chrome_cleaner

Also adds chrome_cleaner_unittests to run the added unit tests (only
enabled on the FYI bot for now). This is a separate test suite because
it will have Chrome Cleaner specific setup added to it as more tests
are added.

Bug: 830892
Change-Id: I33181ac5ad6bba893594838bf1cb77c83cfc69c5
Reviewed-on: https://chromium-review.googlesource.com/1024972
Commit-Queue: Joe Mason <[email protected]>
Reviewed-by: Nico Weber <[email protected]>
Reviewed-by: John Budorick <[email protected]>
Reviewed-by: Chris Sharp <[email protected]>
Cr-Commit-Position: refs/heads/master@{#555207}
diff --git a/BUILD.gn b/BUILD.gn
index fb7dedb6..bb5820f8 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -576,6 +576,7 @@
   if (is_win) {
     deps += [
       "//base:pe_image_test",
+      "//chrome/chrome_cleaner:chrome_cleaner_unittests",
       "//chrome/install_static:install_static_unittests",
       "//chrome/installer/gcapi",
       "//chrome/installer/setup:setup_unittests",