Guard dbus component and config with assert(use_dbus)

chrome/browser/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
 import("//media/media_options.gni")
@@ skipping 849 matching lines @@
     if (toolkit_views) {
       deps += [
         "//ui/views",
         "//ui/views/controls/webview",
       ]
     }
   }
 
   if (is_linux) {
     if (use_aura) {
-      configs += [ "//build/config/linux/dbus" ]
-      deps += [
-        "//build/linux:fontconfig",
-        "//dbus",
-      ]
+      deps += [ "//build/linux:fontconfig" ]
+      if (use_dbus) {
+        deps += [ "//dbus" ]
+      }
     }
     if (use_x11) {
       configs += [ "//build/config/linux:x11" ]
       deps += [ "//ui/gfx/x" ]
     }
   }
 
   if (is_linux || is_win) {
     sources += rebase_path(gypi_values.chrome_browser_non_mac_desktop_sources,
                            ".",
@@ skipping 455 matching lines @@
         rebase_path(gypi_values.chrome_browser_rlz_sources, ".", "//chrome")
     deps = [
       "//components/google/core/browser",
       "//components/omnibox/browser",
       "//components/rlz",
       "//components/search_engines",
       "//rlz:rlz_lib",
     ]
   }
 }