[tracing] Add trace events filtering predicate for heap profiler

base/trace_event/heap_profiler_allocation_context_tracker_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 
 #include <iterator>
 
 #include "base/memory/ref_counted.h"
 #include "base/pending_task.h"
@@ skipping 45 matching lines @@
       AllocationContextTracker::GetInstanceForCurrentThread()
           ->GetContextSnapshot();
 
   ASSERT_EQ(1u, ctx.backtrace.frame_count);
   ASSERT_EQ(t, ctx.backtrace.frames[0]);
 }
 
 class AllocationContextTrackerTest : public testing::Test {
  public:
   void SetUp() override {
-    TraceConfig config("");
+    TraceConfig config(
+        "{ \"event_filters\":[{"
+          "\"included_categories\":["
+            "\"Testing\","
+            "\"disabled-by-default-Testing\""
+          "],"
+          "\"filter_predicate\":\"heap_profiler_predicate\""
+        "}] }");
     TraceLog::GetInstance()->SetEnabled(config, TraceLog::RECORDING_MODE);
     AllocationContextTracker::SetCaptureMode(
         AllocationContextTracker::CaptureMode::PSEUDO_STACK);
     AllocationContextTracker::SetCurrentThreadName(kThreadName);
   }
 
   void TearDown() override {
     AllocationContextTracker::SetCaptureMode(
         AllocationContextTracker::CaptureMode::DISABLED);
     TraceLog::GetInstance()->SetDisabled();
@@ skipping 22 matching lines @@
     }
 
     AssertBacktraceEquals(frame_c);
 
     {
       TRACE_EVENT0("Testing", kEclair);
       StackFrame frame_ce[] = {t, c, e};
       AssertBacktraceEquals(frame_ce);
     }
 
+    {
+      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("Testing"), kCupcake);
+      StackFrame frame_ce[] = {t, c, c};
+      AssertBacktraceEquals(frame_ce);
+    }
+
     AssertBacktraceEquals(frame_c);
   }
 
   AssertBacktraceContainsOnlyThreadName();
 
   {
     TRACE_EVENT0("Testing", kFroyo);
     StackFrame frame_f[] = {t, f};
     AssertBacktraceEquals(frame_f);
   }
@@ skipping 157 matching lines @@
       AllocationContextTracker::GetInstanceForCurrentThread()
           ->GetContextSnapshot();
   const StringPiece kTracingOverhead("tracing_overhead");
   ASSERT_EQ(kTracingOverhead,
             static_cast<const char*>(ctx.backtrace.frames[0].value));
   ASSERT_EQ(1u, ctx.backtrace.frame_count);
 }
 
 }  // namespace trace_event
 }  // namespace base