Bug 1766646 - Vendor libwebrtc from ff7913204c - moz.build file updates

CLOBBER

@@ -22,5 +22,5 @@
 # changes to stick? As of bug 928195, this shouldn't be necessary! Please
 # don't change CLOBBER for WebIDL changes any more.
 
-Modified build files in third_party/libwebrtc - Bug 1766646 - Vendor libwebrtc from 38e9b06151
+Modified build files in third_party/libwebrtc - Bug 1766646 - Vendor libwebrtc from ff7913204c
 

third_party/libwebrtc/moz.build

@@ -307,7 +307,6 @@ DIRS += [
     "/third_party/libwebrtc/rtc_base/protobuf_utils_gn",
     "/third_party/libwebrtc/rtc_base/rate_limiter_gn",
     "/third_party/libwebrtc/rtc_base/refcount_gn",
-    "/third_party/libwebrtc/rtc_base/robo_caller_gn",
     "/third_party/libwebrtc/rtc_base/rtc_base_approved_gn",
     "/third_party/libwebrtc/rtc_base/rtc_base_gn",
     "/third_party/libwebrtc/rtc_base/rtc_event_gn",
@@ -324,7 +323,6 @@ DIRS += [
     "/third_party/libwebrtc/rtc_base/synchronization/yield_gn",
     "/third_party/libwebrtc/rtc_base/synchronization/yield_policy_gn",
     "/third_party/libwebrtc/rtc_base/system/arch_gn",
-    "/third_party/libwebrtc/rtc_base/system/assume_gn",
     "/third_party/libwebrtc/rtc_base/system/file_wrapper_gn",
     "/third_party/libwebrtc/rtc_base/system/ignore_warnings_gn",
     "/third_party/libwebrtc/rtc_base/system/inline_gn",
@@ -342,7 +340,6 @@ DIRS += [
     "/third_party/libwebrtc/rtc_base/timeutils_gn",
     "/third_party/libwebrtc/rtc_base/type_traits_gn",
     "/third_party/libwebrtc/rtc_base/units/unit_base_gn",
-    "/third_party/libwebrtc/rtc_base/untyped_function_gn",
     "/third_party/libwebrtc/rtc_base/weak_ptr_gn",
     "/third_party/libwebrtc/system_wrappers/field_trial_gn",
     "/third_party/libwebrtc/system_wrappers/metrics_gn",