Use Xvfb in isolated testing only if use_x11 is set

content/content_unittests.isolate

Index: content/content_unittests.isolate
diff --git a/content/content_unittests.isolate b/content/content_unittests.isolate
index bc982e2c3dd9239f34ab680f63ffd9ee6528bf8b..ff40dc753beb45bd819d88900ae949109c979c32 100644
--- a/content/content_unittests.isolate
+++ b/content/content_unittests.isolate
@@ -33,7 +33,19 @@
         ],
       },
     }],
-    ['OS=="linux"', {
+    ['use_x11==0', {
+      'variables': {
+        'command': [
+          '../testing/test_env.py',
+          '<(PRODUCT_DIR)/content_unittests<(EXECUTABLE_SUFFIX)',
+          '--brave-new-test-launcher',
+          '--test-launcher-bot-mode',
+          '--asan=<(asan)',
+          '--lsan=<(lsan)',
+        ],
+      },
+    }],
+    ['use_x11==1', {
       'variables': {
         'command': [
           '../testing/xvfb.py',
@@ -46,28 +58,20 @@
         ],
         'files': [
           '../testing/xvfb.py',
-          '<(PRODUCT_DIR)/libffmpegsumo.so',
-          '<(PRODUCT_DIR)/libosmesa.so',
+          '<(PRODUCT_DIR)/xdisplaycheck<(EXECUTABLE_SUFFIX)',
         ],
       },
     }],
-    ['OS=="linux" and use_ozone==0', {
+    ['OS=="linux"', {
       'variables': {
         'files': [
-          '<(PRODUCT_DIR)/xdisplaycheck<(EXECUTABLE_SUFFIX)',
+          '<(PRODUCT_DIR)/libffmpegsumo.so',
+          '<(PRODUCT_DIR)/libosmesa.so',
         ],
       },
     }],
     ['OS=="mac"', {
       'variables': {
-        'command': [
-          '../testing/test_env.py',
-          '<(PRODUCT_DIR)/content_unittests<(EXECUTABLE_SUFFIX)',
-          '--brave-new-test-launcher',
-          '--test-launcher-bot-mode',
-          '--asan=<(asan)',
-          '--lsan=<(lsan)',
-        ],
         'files': [
           '<(PRODUCT_DIR)/ffmpegsumo.so',
           '<(PRODUCT_DIR)/osmesa.so',
@@ -76,14 +80,6 @@
     }],
     ['OS=="win"', {
       'variables': {
-        'command': [
-          '../testing/test_env.py',
-          '<(PRODUCT_DIR)/content_unittests<(EXECUTABLE_SUFFIX)',
-          '--brave-new-test-launcher',
-          '--test-launcher-bot-mode',
-          '--asan=<(asan)',
-          '--lsan=<(lsan)',
-        ],
         'files': [
           '<(PRODUCT_DIR)/ffmpegsumo.dll',
           '<(PRODUCT_DIR)/osmesa.dll',