[memory-infra] Implement peak detection logic

base/trace_event/memory_dump_manager_unittest.cc

Index: base/trace_event/memory_dump_manager_unittest.cc
diff --git a/base/trace_event/memory_dump_manager_unittest.cc b/base/trace_event/memory_dump_manager_unittest.cc
index 51d41943fba0416fd9ad5f167d78cbbbdbc51a1c..a7d952e39dc6fa21bd9cdb9250892f568805016a 100644
--- a/base/trace_event/memory_dump_manager_unittest.cc
+++ b/base/trace_event/memory_dump_manager_unittest.cc
@@ -770,7 +770,7 @@ TEST_F(MemoryDumpManagerTest, TestPollingOnDumpThread) {
       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,