Revert of [tracing] Add filtering mode in TraceLog

base/trace_event/memory_dump_manager.cc

Index: base/trace_event/memory_dump_manager.cc
diff --git a/base/trace_event/memory_dump_manager.cc b/base/trace_event/memory_dump_manager.cc
index 28d5d56c59d4346a9cb740d55fbbeca5aef6b603..9719a6c672086ad9fc9f1c0d815c0b127efcb430 100644
--- a/base/trace_event/memory_dump_manager.cc
+++ b/base/trace_event/memory_dump_manager.cc
@@ -201,33 +201,10 @@
                        nullptr);
 #endif
 
-  TRACE_EVENT_WARMUP_CATEGORY(kTraceCategory);
-
-  // TODO(ssid): This should be done in EnableHeapProfiling so that we capture
-  // more allocations (crbug.com/625170).
-  if (AllocationContextTracker::capture_mode() ==
-          AllocationContextTracker::CaptureMode::PSEUDO_STACK &&
-      !(TraceLog::GetInstance()->enabled_modes() & TraceLog::FILTERING_MODE)) {
-    // Create trace config with heap profiling filter.
-    TraceConfig::EventFilterConfig heap_profiler_filter_config(
-        TraceLog::TraceEventFilter::kHeapProfilerPredicate);
-    heap_profiler_filter_config.AddIncludedCategory("*");
-    heap_profiler_filter_config.AddIncludedCategory(
-        MemoryDumpManager::kTraceCategory);
-    TraceConfig::EventFilters filters;
-    filters.push_back(heap_profiler_filter_config);
-    TraceConfig filtering_trace_config;
-    filtering_trace_config.SetEventFilters(filters);
-
-    TraceLog::GetInstance()->SetEnabled(filtering_trace_config,
-                                        TraceLog::FILTERING_MODE);
-  }
-
   // If tracing was enabled before initializing MemoryDumpManager, we missed the
   // OnTraceLogEnabled() event. Synthetize it so we can late-join the party.
-  // IsEnabled is called before adding observer to avoid calling
-  // OnTraceLogEnabled twice.
   bool is_tracing_already_enabled = TraceLog::GetInstance()->IsEnabled();
+  TRACE_EVENT0(kTraceCategory, "init");  // Add to trace-viewer category list.
   TraceLog::GetInstance()->AddEnabledStateObserver(this);
   if (is_tracing_already_enabled)
     OnTraceLogEnabled();