Tracing pre-filtering

base/trace_event/trace_event_unittest.cc

Index: base/trace_event/trace_event_unittest.cc
diff --git a/base/trace_event/trace_event_unittest.cc b/base/trace_event/trace_event_unittest.cc
index 6a1d8a4991d28952f25e900e7378c48cd6ef80f9..bab27870cf8c25279f475eaa17e2122b8f1dc669 100644
--- a/base/trace_event/trace_event_unittest.cc
+++ b/base/trace_event/trace_event_unittest.cc
@@ -3099,5 +3099,37 @@ TEST_F(TraceEventTestFixture, SyntheticDelayConfigurationToString) {
   EXPECT_EQ(filter, config.ToCategoryFilterString());
 }
 
+TEST_F(TraceEventTestFixture, EventFiltering) {
+  const char config_json[] =
+      "{"
+      "  \"included_categories\": ["
+      "    \"filtered_cat\","
+      "    \"unfiltered_cat\"],"
+      "  \"category_event_filters\": ["
+      "     {"
+      "       \"predicate\": \"event_whitelist_predicate\", "
+      "       \"included_categories\": [\"*\"], "
+      "       \"excluded_categories\": [\"unfiltered_cat\"], "
+      "       \"args\": {\"event_name_whitelist\": [\"a snake\", \"a dog\"]}"
+      "     }"
+      "    "
+      "  ]"
+      "}";
+
+  TraceConfig trace_config(config_json);
+  TraceLog::GetInstance()->SetEnabled(trace_config, TraceLog::RECORDING_MODE);
+  EXPECT_TRUE(TraceLog::GetInstance()->IsEnabled());
+
+  TRACE_EVENT0("filtered_cat", "a snake");
+  TRACE_EVENT0("filtered_cat", "a mushroom");
+  TRACE_EVENT0("unfiltered_cat", "a cat");
+
+  EndTraceAndFlush();
+
+  EXPECT_TRUE(FindMatchingValue("name", "a snake"));
+  EXPECT_FALSE(FindMatchingValue("name", "a mushroom"));
+  EXPECT_TRUE(FindMatchingValue("name", "a cat"));
+}
+
 }  // namespace trace_event
 }  // namespace base