tracing: split trace event filter classes out of TraceLog

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 81d043ac3945d3582b0a99c22f4adb22d1bd8a21..7a9d284876ba2f0f322de6a0591169912912f98f 100644
--- a/base/trace_event/trace_event_unittest.cc
+++ b/base/trace_event/trace_event_unittest.cc
@@ -30,8 +30,12 @@
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
+#include "base/trace_event/event_name_filter.h"
+#include "base/trace_event/heap_profiler_event_filter.h"
 #include "base/trace_event/trace_buffer.h"
 #include "base/trace_event/trace_event.h"
+#include "base/trace_event/trace_event_filter.h"
+#include "base/trace_event/trace_event_filter_test_utils.h"
 #include "base/trace_event/trace_event_synthetic_delay.h"
 #include "base/values.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -2956,45 +2960,6 @@ TEST_F(TraceEventTestFixture, SyntheticDelayConfigurationToString) {
   EXPECT_EQ(filter, config.ToCategoryFilterString());
 }
 
-class TestEventFilter : public TraceLog::TraceEventFilter {
- public:
-  bool FilterTraceEvent(const TraceEvent& trace_event) const override {
-    filter_trace_event_hit_count_++;
-    return filter_return_value_;
-  }
-
-  void EndEvent(const char* category_group, const char* name) override {
-    end_event_hit_count_++;
-  }
-
-  static void set_filter_return_value(bool value) {
-    filter_return_value_ = value;
-  }
-
-  static size_t filter_trace_event_hit_count() {
-    return filter_trace_event_hit_count_;
-  }
-  static size_t end_event_hit_count() { return end_event_hit_count_; }
-
-  static void clear_counts() {
-    filter_trace_event_hit_count_ = 0;
-    end_event_hit_count_ = 0;
-  }
-
- private:
-  static size_t filter_trace_event_hit_count_;
-  static size_t end_event_hit_count_;
-  static bool filter_return_value_;
-};
-
-size_t TestEventFilter::filter_trace_event_hit_count_ = 0;
-size_t TestEventFilter::end_event_hit_count_ = 0;
-bool TestEventFilter::filter_return_value_ = false;
-
-std::unique_ptr<TraceLog::TraceEventFilter> ConstructTestEventFilter() {
-  return WrapUnique(new TestEventFilter);
-}
-
 TEST_F(TraceEventTestFixture, TraceFilteringMode) {
   const char config_json[] =
       "{"
@@ -3007,8 +2972,8 @@ TEST_F(TraceEventTestFixture, TraceFilteringMode) {
       "}";
 
   // Run RECORDING_MODE within FILTERING_MODE:
+  TestEventFilter::clear_counts();

[Primiano Tucci (use gerrit), 2016/12/06 14:02:31]

this is purely for test isolation. I think I notice a while ago that if the
other test fails it will subtly cause a mysterious failure here because we don't
get to execute the clear at the end of the other.
So clearing also upfront makes the test easier to understand in this situation.

[kraynov, 2016/12/06 18:24:23]

I would prefer not making stateful design.

[Primiano Tucci (use gerrit), 2016/12/07 11:17:47]

Fixed by splitting out the HitCounter class

   TestEventFilter::set_filter_return_value(true);
-  TraceLog::SetTraceEventFilterConstructorForTesting(ConstructTestEventFilter);
 
   // Only filtering mode is enabled with test filters.
   TraceLog::GetInstance()->SetEnabled(TraceConfig(config_json),
@@ -3111,8 +3076,9 @@ TEST_F(TraceEventTestFixture, EventFiltering) {
       "  ]"
       "}";
 
+  TestEventFilter::clear_counts();
   TestEventFilter::set_filter_return_value(true);
-  TraceLog::SetTraceEventFilterConstructorForTesting(ConstructTestEventFilter);
+
   TraceConfig trace_config(config_json);
   TraceLog::GetInstance()->SetEnabled(
       trace_config, TraceLog::RECORDING_MODE | TraceLog::FILTERING_MODE);
@@ -3150,7 +3116,7 @@ TEST_F(TraceEventTestFixture, EventWhitelistFiltering) {
       "    "
       "  ]"
       "}",
-      TraceLog::TraceEventFilter::kEventWhitelistPredicate);
+      EventNameFilter::kName);
 
   TraceConfig trace_config(config_json);
   TraceLog::GetInstance()->SetEnabled(
@@ -3182,7 +3148,7 @@ TEST_F(TraceEventTestFixture, HeapProfilerFiltering) {
       "     }"
       "  ]"
       "}",
-      TraceLog::TraceEventFilter::kHeapProfilerPredicate);
+      HeapProfilerEventFilter::kName);
 
   TraceConfig trace_config(config_json);
   TraceLog::GetInstance()->SetEnabled(