[tracing] Add trace events filtering predicate for heap profiler

base/trace_event/trace_log.cc

Index: base/trace_event/trace_log.cc
diff --git a/base/trace_event/trace_log.cc b/base/trace_event/trace_log.cc
index a9f99d41f0dc97b37a1cc7364c30231451047088..2828ca1a2ffbe185e75a9739600d29a5d29a6392 100644
--- a/base/trace_event/trace_log.cc
+++ b/base/trace_event/trace_log.cc
@@ -133,6 +133,36 @@ base::LazyInstance<
     std::list<std::unique_ptr<TraceLog::TraceEventFilter>>>::Leaky
     g_category_group_filter[MAX_CATEGORY_GROUPS] = {LAZY_INSTANCE_INITIALIZER};
 
+class HeapProfilerFilter : public TraceLog::TraceEventFilter {
+ public:
+  HeapProfilerFilter() {}
+
+  bool FilterTraceEvent(const TraceEvent& trace_event) const override {
+    // TODO(primiano): Add support for events with copied name crbug.com/581078
+    if (!(trace_event.flags() & TRACE_EVENT_FLAG_COPY)) {
+      if (AllocationContextTracker::capture_mode() ==
+          AllocationContextTracker::CaptureMode::PSEUDO_STACK) {
+        if (trace_event.phase() == TRACE_EVENT_PHASE_BEGIN ||
+            trace_event.phase() == TRACE_EVENT_PHASE_COMPLETE) {
+          AllocationContextTracker::GetInstanceForCurrentThread()
+              ->PushPseudoStackFrame(trace_event.name());
+        } else if (trace_event.phase() == TRACE_EVENT_PHASE_END)
+          // The pop for |TRACE_EVENT_PHASE_COMPLETE| events is in |EndEvent|.
+          AllocationContextTracker::GetInstanceForCurrentThread()
+              ->PopPseudoStackFrame(trace_event.name());
+      }
+    }
+    // This predicate does not filter any events, but only records the events.
+    // So, it should return true iff the category is enabled for recoding.
+    return (*trace_event.category_group_enabled() &
+            TraceLog::ENABLED_FOR_RECORDING);
+  }
+  void EndEvent(const char* name, const char* category_group) override {
+    AllocationContextTracker::GetInstanceForCurrentThread()
+        ->PopPseudoStackFrame(name);
+  }
+};
+
 TraceLog::TraceEventFilterConstructorForTesting
     g_trace_event_filter_constructor_for_testing = nullptr;
 
@@ -542,6 +572,8 @@ void TraceLog::UpdateCategoryGroupEnabledFlag(size_t category_index) {
       if (event_filter.predicate_name() == "event_whitelist_predicate") {
         new_filter =
             WrapUnique(new EventNameFilter(event_filter.filter_args()));
+      } else if (event_filter.predicate_name() == "heap_profiler_predicate") {
+        new_filter = WrapUnique(new HeapProfilerFilter());
       } else if (event_filter.predicate_name() == "testing_predicate") {
         CHECK(g_trace_event_filter_constructor_for_testing);
         new_filter = g_trace_event_filter_constructor_for_testing();
@@ -1429,23 +1461,6 @@ TraceEventHandle TraceLog::AddTraceEventWithThreadIdAndTimestamp(
     }
   }
 
-  // TODO(primiano): Add support for events with copied name crbug.com/581078
-  if (!(flags & TRACE_EVENT_FLAG_COPY)) {
-    if (AllocationContextTracker::capture_mode() ==
-        AllocationContextTracker::CaptureMode::PSEUDO_STACK) {
-      if (phase == TRACE_EVENT_PHASE_BEGIN ||
-          phase == TRACE_EVENT_PHASE_COMPLETE) {
-        AllocationContextTracker::GetInstanceForCurrentThread()
-            ->PushPseudoStackFrame(name);
-      } else if (phase == TRACE_EVENT_PHASE_END) {
-        // The pop for |TRACE_EVENT_PHASE_COMPLETE| events
-        // is in |TraceLog::UpdateTraceEventDuration|.
-        AllocationContextTracker::GetInstanceForCurrentThread()
-            ->PopPseudoStackFrame(name);
-      }
-    }
-  }
-
   return handle;
 }
 
@@ -1577,13 +1592,6 @@ void TraceLog::UpdateTraceEventDuration(
       console_message =
           EventToConsoleMessage(TRACE_EVENT_PHASE_END, now, trace_event);
     }
-
-    if (AllocationContextTracker::capture_mode() ==
-        AllocationContextTracker::CaptureMode::PSEUDO_STACK) {
-      // The corresponding push is in |AddTraceEventWithThreadIdAndTimestamp|.
-      AllocationContextTracker::GetInstanceForCurrentThread()
-          ->PopPseudoStackFrame(name);
-    }
   }
 
   if (!console_message.empty())