[tracing] Add browser test for background memory tracing

base/trace_event/trace_config_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 "base/json/json_reader.h"
 #include "base/macros.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/trace_config.h"
@@ skipping 569 matching lines @@
             tc1.memory_dump_config_.triggers[0].level_of_detail);
 
   EXPECT_EQ(2000u, tc1.memory_dump_config_.triggers[1].periodic_interval_ms);
   EXPECT_EQ(MemoryDumpLevelOfDetail::DETAILED,
             tc1.memory_dump_config_.triggers[1].level_of_detail);
   EXPECT_EQ(
       2048u,
       tc1.memory_dump_config_.heap_profiler_options.breakdown_threshold_bytes);
 
   std::string tc_str2 =
-      TraceConfigMemoryTestUtil::GetTraceConfig_BackgroundTrigger();
+      TraceConfigMemoryTestUtil::GetTraceConfig_BackgroundTrigger(
+          1 /* period_ms */);
   TraceConfig tc2(tc_str2);
   EXPECT_EQ(tc_str2, tc2.ToString());
   EXPECT_TRUE(tc2.IsCategoryGroupEnabled(MemoryDumpManager::kTraceCategory));
   ASSERT_EQ(1u, tc2.memory_dump_config_.triggers.size());
   EXPECT_EQ(1u, tc2.memory_dump_config_.triggers[0].periodic_interval_ms);
   EXPECT_EQ(MemoryDumpLevelOfDetail::BACKGROUND,
             tc2.memory_dump_config_.triggers[0].level_of_detail);
 }
 
 TEST(TraceConfigTest, EmptyMemoryDumpConfigTest) {
@@ skipping 14 matching lines @@
   EXPECT_NE(std::string::npos, tc.ToString().find("memory_dump_config"));
   EXPECT_EQ(2u, tc.memory_dump_config_.triggers.size());
   EXPECT_EQ(TraceConfig::MemoryDumpConfig::HeapProfiler
             ::kDefaultBreakdownThresholdBytes,
             tc.memory_dump_config_.heap_profiler_options
             .breakdown_threshold_bytes);
 }
 
 }  // namespace trace_event
 }  // namespace base