memory-infra: Switch to MemoryPeakDetector and simplify MemoryDumpScheduler

base/trace_event/memory_peak_detector.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_peak_detector.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/sys_info.h"
 #include "base/threading/sequenced_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/memory_dump_provider_info.h"
 #include "base/trace_event/trace_event.h"
 
 namespace base {
 namespace trace_event {
 
 // static
 MemoryPeakDetector* MemoryPeakDetector::GetInstance() {
   static MemoryPeakDetector* instance = new MemoryPeakDetector();
   return instance;
 }
 
+// TODO call SuspendFastMemoryPolling, both when unregistering and stopping.
+
 MemoryPeakDetector::MemoryPeakDetector()
     : generation_(0),
       state_(NOT_INITIALIZED),
       poll_tasks_count_for_testing_(0) {}
 
 MemoryPeakDetector::~MemoryPeakDetector() {
   // This is hit only in tests, in which case the test is expected to TearDown()
   // cleanly and not leave the peak detector running.
   DCHECK_EQ(NOT_INITIALIZED, state_);
 }
@@ skipping 210 matching lines @@
 }
 
 void MemoryPeakDetector::SetStaticThresholdForTesting(
     uint64_t static_threshold_bytes) {
   DCHECK_EQ(DISABLED, state_);
   static_threshold_bytes_ = static_threshold_bytes;
 }
 
 }  // namespace trace_event
 }  // namespace base