Try UWP with msvc.

The UWP toolchain code appears to be broken with clang, so let's see
if we have better luck with MSVC.

Bug: webrtc:10050
Change-Id: If8d29e7a95a0780c310ccd665c99d7a3add1016a
Reviewed-on: https://webrtc-review.googlesource.com/c/112290
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Commit-Queue: Patrik Höglund <phoglund@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25841}
diff --git a/tools_webrtc/mb/mb_config.pyl b/tools_webrtc/mb/mb_config.pyl
index d045dc4..ac04ba5 100644
--- a/tools_webrtc/mb/mb_config.pyl
+++ b/tools_webrtc/mb/mb_config.pyl
@@ -352,7 +352,7 @@
     ],
     'win_uwp_release_bot_x64': [
       # UWP passes compiler flags that are not supported by goma.
-      'gn', 'clang', 'openh264', 'x64', 'winuwp', 'release_bot_no_goma'
+      'gn', 'no_clang', 'openh264', 'x64', 'winuwp', 'release_bot_no_goma'
     ],
 
     # Mac
@@ -500,6 +500,10 @@
       'gn_args': 'use_goma=true',
     },
 
+    'no_goma': {
+      'gn_args': 'use_goma=false',
+    },
+
     'libfuzzer': {
       'gn_args': 'use_libfuzzer=true',
     },
@@ -550,7 +554,7 @@
     },
 
     'release_bot_no_goma': {
-      'mixins': ['release', 'dcheck_always_on'],
+      'mixins': ['release', 'no_goma', 'dcheck_always_on'],
     },
 
     'tsan': {