Use Xvfb in isolated testing only if use_x11 is set (reland)

ui/events/events_unittests.isolate

Index: ui/events/events_unittests.isolate
diff --git a/ui/events/events_unittests.isolate b/ui/events/events_unittests.isolate
index 2a0549c882077986e0ee457c9e867b7d96be24e7..11808e20078a66f8e15c0f480d910e99ae99d83c 100644
--- a/ui/events/events_unittests.isolate
+++ b/ui/events/events_unittests.isolate
@@ -11,7 +11,21 @@
         ],
       },
     }],
-    ['OS=="linux"', {
+    ['use_x11==0', {
+      'variables': {
+        'command': [
+          '../../testing/test_env.py',
+          '<(PRODUCT_DIR)/events_unittests<(EXECUTABLE_SUFFIX)',
+          '--brave-new-test-launcher',
+          '--test-launcher-bot-mode',
+          '--asan=<(asan)',
+          '--lsan=<(lsan)',
+          '--msan=<(msan)',
+          '--tsan=<(tsan)',
+        ],
+      },
+    }],
+    ['use_x11==1', {
       'variables': {
         'command': [
           '../../testing/xvfb.py',
@@ -26,14 +40,14 @@
         ],
         'files': [
           '../../testing/xvfb.py',
-          '<(PRODUCT_DIR)/libosmesa.so',
+          '<(PRODUCT_DIR)/xdisplaycheck<(EXECUTABLE_SUFFIX)',
         ],
       },
     }],
     ['OS=="linux" and use_ozone==0', {
       'variables': {
         'files': [
-          '<(PRODUCT_DIR)/xdisplaycheck<(EXECUTABLE_SUFFIX)',
+          '<(PRODUCT_DIR)/libosmesa.so',
         ],
       },
     }],
@@ -51,20 +65,6 @@
         ],
       },
     }],
-    ['OS=="mac" or OS=="win"', {
-      'variables': {
-        'command': [
-          '../../testing/test_env.py',
-          '<(PRODUCT_DIR)/events_unittests<(EXECUTABLE_SUFFIX)',
-          '--brave-new-test-launcher',
-          '--test-launcher-bot-mode',
-          '--asan=<(asan)',
-          '--lsan=<(lsan)',
-          '--msan=<(msan)',
-          '--tsan=<(tsan)',
-        ],
-      },
-    }],
     ['OS=="mac" and asan==1 and fastbuild==0', {
       'variables': {
         'files': [