Print max RSS in GM and nanobench too.

Everyone used MB, so update the API to just return that.

BUG=skia:
R=halcanary@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/483323002
diff --git a/gm/gmmain.cpp b/gm/gmmain.cpp
index 7f012bc..674cab9 100644
--- a/gm/gmmain.cpp
+++ b/gm/gmmain.cpp
@@ -18,6 +18,7 @@
 #include "gm_expectations.h"
 #include "system_preferences.h"
 #include "CrashHandler.h"
+#include "ProcStats.h"
 #include "Resources.h"
 #include "SamplePipeControllers.h"
 #include "SkBitmap.h"
@@ -2386,10 +2387,11 @@
 
         gmsRun++;
         SkISize size = gm->getISize();
-        SkDebugf("%sdrawing... %s [%d %d]\n", moduloStr.c_str(), shortName,
+        SkDebugf("%4dM %sdrawing... %s [%d %d]\n",
+                 sk_tools::getMaxResidentSetSizeMB(), moduloStr.c_str(), shortName,
                  size.width(), size.height());
         if (!FLAGS_dryRun)
-            run_multiple_configs(gmmain, gm, configs, pdfRasterizers, tileGridReplayScales, 
+            run_multiple_configs(gmmain, gm, configs, pdfRasterizers, tileGridReplayScales,
                                  grFactory, gpuAPI);
     }