[gn] Add cctest

BUG=chromium:474921
NOTRY=true

Committed: https://crrev.com/52a6fced896e3f64ac56eb57bcdea78393642e0c
Cr-Commit-Position: refs/heads/master@{#36517}

Review-Url: https://codereview.chromium.org/2007143003
Cr-Commit-Position: refs/heads/master@{#36586}

BUILD.gn

@@ -2070,6 +2070,7 @@ group("gn_all") {
   if (host_os != "mac" || !is_android) {
     # These items don't compile for Android on Mac.
     deps += [
+      "test/cctest:cctest",
       "test/unittests:unittests",
     ]
   }