[dart:io] Adds ProcessInfo.{max,current}Rss. Adds OS::MaxRSS on Fuchsia.

runtime/bin/process_win.cc

Index: runtime/bin/process_win.cc
diff --git a/runtime/bin/process_win.cc b/runtime/bin/process_win.cc
index 56cd57d6b164b57539d914f76217e742a804f343..4c3f24332a636216e5008669a2b3cfb78d6ceba0 100644
--- a/runtime/bin/process_win.cc
+++ b/runtime/bin/process_win.cc
@@ -941,6 +941,24 @@ intptr_t Process::CurrentProcessId() {
 }
 
 
+intptr_t Process::CurrentRss() {
+  PROCESS_MEMORY_COUNTERS pmc;
+  if (!GetProcessMemoryInfo(GetCurrentProcess(), &info, sizeof(pmc))) {
+    return -1;
+  }
+  return pmc.WorkingSetSize;
+}
+
+
+intptr_t Process::MaxRSS() {
+  PROCESS_MEMORY_COUNTERS pmc;
+  if (!GetProcessMemoryInfo(GetCurrentProcess(), &pmc, sizeof(pmc))) {
+    return -1;
+  }
+  return pmc.PeakWorkingSetSize;
+}
+
+
 static SignalInfo* signal_handlers = NULL;
 static Mutex* signal_mutex = new Mutex();