Add 'chrome_official_builder' target to //BUILD.gn.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index d03a777314bc0bad0fd496452508aeb8277a9ce6..40afb32a5cd3d8f3f9703273c60be4bc8438e5de 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -113,6 +113,29 @@ if (is_win) {
       deps += [ "//remoting/host:remoting_host_installation" ]
     }
   }
+
+  group("chrome_official_builder") {
+    testonly = true
+
+    deps = [
+      ":chrome_official_builder_no_unittests",
+      "//base:base_unittests",
+      "//chrome/test:browser_tests",
+      "//chrome/test:sync_integration_tests",
+      "//ipc:ipc_tests",
+      "//media:media_unittests",
+      "//media/midi:midi_unittests",
+      "//net:net_unittests",
+      "//printing:printing_unittests",
+      "//sql:sql_unittests",
+      "//sync:sync_unit_tests",
+      "//ui/base:ui_base_unittests",
+      "//ui/gfx:gfx_unittests",
+      "//ui/touch_selection:ui_touch_selection_unittests",
+      "//ui/views:views_unittests",
+      "//url:url_unittests",
+    ]
+  }
 }
 
 if (is_chromeos) {