memory-infra: Add peak-detector skeleton.

Adds a skeleton and tests for the MemoryPeakDetector.
This CL does not yet take over the old peak detector in
MemoryDumpScheduler, which will happen in the next CLs.

BUG=607533
TBR=thakis@chromium.org

Review-Url: https://codereview.chromium.org/2786373002
Cr-Original-Commit-Position: refs/heads/master@{#461678}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: f34c3e056c9a2eaa12a41daa2f8e05b579360f28
diff --git a/tools/gn/bootstrap/bootstrap.py b/tools/gn/bootstrap/bootstrap.py
index b680217..937427c 100755
--- a/tools/gn/bootstrap/bootstrap.py
+++ b/tools/gn/bootstrap/bootstrap.py
@@ -522,6 +522,7 @@
       'base/trace_event/memory_dump_scheduler.cc',
       'base/trace_event/memory_dump_session_state.cc',
       'base/trace_event/memory_infra_background_whitelist.cc',
+      'base/trace_event/memory_peak_detector.cc',
       'base/trace_event/process_memory_dump.cc',
       'base/trace_event/process_memory_maps.cc',
       'base/trace_event/process_memory_totals.cc',