Remove unused dbus.cc/.h and related things.

webrtc/BUILD.gn

Index: webrtc/BUILD.gn
diff --git a/webrtc/BUILD.gn b/webrtc/BUILD.gn
index 2becbc74ea9d5a03a0cb5c9a98908043076d3319..183e18593d237161994997ff734fab24825841d2 100644
--- a/webrtc/BUILD.gn
+++ b/webrtc/BUILD.gn
@@ -97,12 +97,6 @@ config("common_inherited_config") {
   # }
 }
 
-if (rtc_have_dbus_glib) {
-  pkg_config("dbus-glib") {
-    packages = [ "dbus-glib-1" ]
-  }
-}
-
 config("common_config") {
   cflags = []
   cflags_cc = []
@@ -116,16 +110,6 @@ config("common_config") {
     defines += [ "WEBRTC_INCLUDE_INTERNAL_AUDIO_DEVICE" ]
   }
 
-  if (rtc_have_dbus_glib) {
-    defines += [ "HAVE_DBUS_GLIB" ]
-
-    # TODO(kjellander): Investigate this, it seems like include <dbus/dbus.h>
-    # is still not found even if the execution of
-    # build/config/linux/pkg-config.py dbus-glib-1 returns correct include
-    # dirs on Linux.
-    all_dependent_configs = [ "dbus-glib" ]
-  }
-
   if (rtc_relative_path) {
     defines += [ "EXPAT_RELATIVE_PATH" ]
   }