[GN] content_unittests should depeng on //content/common

content/test/BUILD.gn

Index: content/test/BUILD.gn
diff --git a/content/test/BUILD.gn b/content/test/BUILD.gn
index 1825beed27ed48597b34d528ee32b63ba300d50c..e56ba2ea3adb2374c3ee6c82309d784c3f171d91 100644
--- a/content/test/BUILD.gn
+++ b/content/test/BUILD.gn
@@ -654,6 +654,7 @@ test("content_unittests") {
     "//content/browser/service_worker:service_worker_proto",
     "//content/browser/speech/proto",
     "//content/child:for_content_tests",
+    "//content/common",
     "//content/common:mojo_bindings",
     "//content/gpu",
     "//content/public/browser",