Disallow blink/public/common/ to depend back on blink/common/.

The blink public API should not expose internal blink types outside
of blink. By disallowing this dependency by default we avoid
accidentally exposing those types.

Change-Id: I68883f3d7716b2309cadf32db8e5599d2fe5c8cb
Reviewed-on: https://chromium-review.googlesource.com/1028573
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553936}

third_party/blink/public/common/DEPS

@@ -10,8 +10,11 @@ include_rules = [
     "+build",
     "+net",
     "+mojo",
-    "+third_party/blink/common",
     "+third_party/blink/public/common",
     "+third_party/blink/public/mojom",
     "+url",
+
+    # This file should not be included outside of blink, so it does not belong
+    # in blink/public.
+    "+third_party/blink/common/common_export.h",
 ]