[memory-infra] Implement peak detection logic

base/trace_event/memory_dump_manager_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 "base/trace_event/memory_dump_manager.h"
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
@@ skipping 752 matching lines @@
 
   MemoryDumpProvider::Options options;
   options.is_fast_polling_supported = true;
   RegisterDumpProvider(mdp1.get(), nullptr, options);
 
   RunLoop run_loop;
   scoped_refptr<SingleThreadTaskRunner> test_task_runner =
       ThreadTaskRunnerHandle::Get();
   auto quit_closure = run_loop.QuitClosure();
 
-  const int kPollsToQuit = 10;
+  const int kPollsToQuit = 60;

[Primiano Tucci (use gerrit), 2017/03/10 10:19:32]

out of curiosity, why? isn't this going to make the test a bit too long?

[ssid, 2017/03/10 19:49:01]

Thought more about it and it does not help the testing here. I am writing some
more unittests to cover cases better.

   int call_count = 0;
   MemoryDumpManager* mdm = mdm_.get();
   const auto poll_function1 = [&call_count, &test_task_runner, quit_closure,
                                &mdp2, mdm, &options, kPollsToQuit,
                                this](uint64_t* total) -> void {
     ++call_count;
     if (call_count == 1)
       RegisterDumpProvider(mdp2.get(), nullptr, options, kMDPName);
     else if (call_count == 4)
       mdm->UnregisterAndDeleteDumpProviderSoon(std::move(mdp2));
@@ skipping 502 matching lines @@
   thread.Start();
   RegisterDumpProvider(&mdp1, thread.task_runner(), kDefaultOptions,
                        "BlacklistTestDumpProvider");
   // Unregistering on wrong thread should not crash.
   mdm_->UnregisterDumpProvider(&mdp1);
   thread.Stop();
 }
 
 }  // namespace trace_event
 }  // namespace base