Componentize chrome/common/content_settings files.

components/content_settings/core/common/BUILD.gn

Index: components/content_settings/core/common/BUILD.gn
diff --git a/components/content_settings/core/common/BUILD.gn b/components/content_settings/core/common/BUILD.gn
index 7c7d0a1e7e0af0f46bc64d29342a57f1fd40c655..797a73b10596f41bf9d53e613349734a963f65b7 100644
--- a/components/content_settings/core/common/BUILD.gn
+++ b/components/content_settings/core/common/BUILD.gn
@@ -2,8 +2,21 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("common") {
+static_library("common") {
   sources = [
+    "content_settings.cc",
+    "content_settings.h",
+    "content_settings_pattern.cc",
+    "content_settings_pattern.h",
+    "content_settings_pattern_parser.cc",
+    "content_settings_pattern_parser.h",
     "content_settings_types.h",
   ]
 }
+
+source_set("unit_tests") {
+  sources = [
+    "content_settings_pattern_unittest.cc",
+    "content_settings_pattern_parser_unittest.cc",
+  ]
+}