Guard dbus component and config with assert(use_dbus)

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index 26bb379a84cf9c3a55ea48d126640ca08c45eb9f..8c16411e3d0127af9057c2b5ea98b8920845070b 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -1113,10 +1113,15 @@ if (!is_android) {
         "//chromeos/ime:gencode",
         "//components/arc:arc_test_support",
         "//components/user_manager:test_support",
-        "//dbus",
-        "//dbus:test_support",
         "//ui/login:resources",
       ]
+
+      if (use_dbus) {
+        deps += [
+          "//dbus",

[brettw, 2016/05/31 20:22:37]

You can remove this and just keep test support since you're touching it. The
convention is that the test_support version has a public dep on the
corresponding non-test target (and dbus does) so that only it is necessary.

[mbjorge, 2016/05/31 20:38:39]

Done

+          "//dbus:test_support",
+        ]
+      }
     } else {
       sources -= [
         "../browser/extensions/api/enterprise_device_attributes/enterprise_device_attributes_apitest.cc",
@@ -2044,11 +2049,13 @@ test("unit_tests") {
     deps += [ "//third_party/libsecret" ]
   }
   if (is_linux && use_aura) {
-    deps += [
-      "//dbus",
-      "//dbus:test_support",
-      "//ui/aura:test_support",
-    ]
+    deps += [ "//ui/aura:test_support" ]
+    if (use_dbus) {
+      deps += [
+        "//dbus",

[brettw, 2016/05/31 20:22:37]

Ditto

[mbjorge, 2016/05/31 20:38:39]

Done

+        "//dbus:test_support",
+      ]
+    }
   }
   if (is_linux && is_chrome_branded && current_cpu == "x86") {
     ldflags = [ "-Wl,--strip-debug" ]