[test] Skip some tests on the coverage bot.

test/webkit/webkit.status

Index: test/webkit/webkit.status
diff --git a/test/webkit/webkit.status b/test/webkit/webkit.status
index 903698892c16798249647491ed1a5d3fcf91fd99..6c3f402d63c4184799029bd5550593e7e24fe8fe 100644
--- a/test/webkit/webkit.status
+++ b/test/webkit/webkit.status
@@ -95,4 +95,11 @@
 }],  # 'gc_stress == True and mode == debug'
 
 ##############################################################################
+['gcov_coverage', {
+  # Tests taking too long or getting too large call stacks.
+  'fast/js/excessive-comma-usage': [SKIP],
+  'run-json-stringify': [SKIP],
+}],  # 'gcov_coverage'
+
+##############################################################################
 ]