memory-infra: remove light dumps and increment default dump time to 5s

base/trace_event/memory_dump_scheduler.cc

 // Copyright 2017 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 "base/trace_event/memory_dump_scheduler.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/bind.h"
@@ skipping 55 matching lines @@
 
   DCHECK_EQ(0u, light_dump_period_ms % min_period_ms);
   DCHECK_EQ(0u, heavy_dump_period_ms % min_period_ms);
   DCHECK(!config.callback.is_null());
   callback_ = config.callback;
   period_ms_ = min_period_ms;
   tick_count_ = 0;
   light_dump_rate_ = light_dump_period_ms / min_period_ms;
   heavy_dump_rate_ = heavy_dump_period_ms / min_period_ms;
 
-  // Trigger the first dump after |period_ms_| and not as soon as timer starts.
-  SequencedTaskRunnerHandle::Get()->PostDelayedTask(
+  // Trigger the first dump immediately.
+  SequencedTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
-      BindOnce(&MemoryDumpScheduler::Tick, Unretained(this), ++generation_),
-      TimeDelta::FromMilliseconds(period_ms_));
+      BindOnce(&MemoryDumpScheduler::Tick, Unretained(this), ++generation_));
 }
 
 void MemoryDumpScheduler::StopInternal() {
   period_ms_ = 0;
   generation_++;
   callback_.Reset();
 }
 
 void MemoryDumpScheduler::Tick(uint32_t expected_generation) {
   if (period_ms_ == 0 || generation_ != expected_generation)
@@ skipping 15 matching lines @@
   callback_.Run(level_of_detail);
 }
 
 MemoryDumpScheduler::Config::Config() {}
 MemoryDumpScheduler::Config::~Config() {}
 MemoryDumpScheduler::Config::Config(const MemoryDumpScheduler::Config&) =
     default;
 
 }  // namespace trace_event
 }  // namespace base