Enable UMA histogram logger for low memor kill events in ArcMetricsService.

chrome/test/nacl/nacl_browsertest.cc

Index: chrome/test/nacl/nacl_browsertest.cc
diff --git a/chrome/test/nacl/nacl_browsertest.cc b/chrome/test/nacl/nacl_browsertest.cc
index 784165ca96151c51a9cafc4c9707b68c8aba6621..ee6a08b12a6600edc6f17462f7de010f3410cab8 100644
--- a/chrome/test/nacl/nacl_browsertest.cc
+++ b/chrome/test/nacl/nacl_browsertest.cc
@@ -192,7 +192,8 @@ base::FilePath::StringType NumberOfCoresAsFilePathString() {
   long nprocessors = sysconf(_SC_NPROCESSORS_ONLN);
 #if TELEMETRY
   fprintf(stderr, "browser says nprocessors = %ld\n", nprocessors);
-  fflush(NULL);
+  // crbug.com/597899

[Mark Seaborn, 2016/03/25 21:26:25]

This reference isn't really necessary -- the absence of a fflush(NULL) call
doesn't require an explanation. :-)

[cylee1, 2016/03/25 21:34:03]

Ye.. But anyway I think it doesn't hurt to keep it.
In case somebody is tracing the log and wondering why the change. Or even
worse... if somebody wants to change it back ... ha..

+  fflush(stderr);
 #endif
   snprintf(string_rep, sizeof string_rep, "%ld", nprocessors);
   return string_rep;
@@ -205,7 +206,8 @@ base::FilePath::StringType NumberOfCoresAsFilePathString() {
 #if TELEMETRY
   fprintf(stderr, "browser says nprocessors = %lu\n",
           system_info.dwNumberOfProcessors);
-  fflush(NULL);
+  // crbug.com/597899
+  fflush(stderr);
 #endif
   _snwprintf_s(string_rep, sizeof string_rep / sizeof string_rep[0], _TRUNCATE,
                L"%u", system_info.dwNumberOfProcessors);
@@ -216,11 +218,12 @@ base::FilePath::StringType NumberOfCoresAsFilePathString() {
 #if TELEMETRY
 static void PathTelemetry(base::FilePath::StringType const &path) {
 # if defined(OS_WIN)
-    fwprintf(stderr, L"path = %s\n", path.c_str());
+  fwprintf(stderr, L"path = %s\n", path.c_str());
 # else
-    fprintf(stderr, "path = %s\n", path.c_str());
+  fprintf(stderr, "path = %s\n", path.c_str());
 # endif
-    fflush(NULL);
+  // crbug.com/597899
+  fflush(stderr);
 }
 #else
 static void PathTelemetry(base::FilePath::StringType const &path) {