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

chrome/test/nacl/nacl_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdio.h>
 #if defined(OS_POSIX)
 #include <unistd.h>
 #elif defined(OS_WIN)
 #include <windows.h>
 #endif
@@ skipping 174 matching lines @@
 // conditionals inside the argument of a macro, so we put the
 // conditionals on a helper function.  We are already in an anonymous
 // namespace, so the name of the helper is not visible in external
 // scope.
 #if defined(OS_POSIX)
 base::FilePath::StringType NumberOfCoresAsFilePathString() {
   char string_rep[23];
   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;
 }
 #elif defined(OS_WIN)
 base::FilePath::StringType NumberOfCoresAsFilePathString() {
   wchar_t string_rep[23];
   SYSTEM_INFO system_info;
   GetSystemInfo(&system_info);
 #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);
   return string_rep;
 }
 #endif
 
 #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) {
   (void) path;
 }
 #endif
 
 NACL_BROWSER_TEST_F(NaClBrowserTest, MAYBE_SysconfNprocessorsOnln, {
     base::FilePath::StringType path =
       FILE_PATH_LITERAL("sysconf_nprocessors_onln_test.html?cpu_count=");
@@ skipping 194 matching lines @@
 }
 
 // TODO(ncbray) support glibc and PNaCl
 // flaky: crbug.com/375894
 IN_PROC_BROWSER_TEST_F(NaClBrowserTestNewlibExtension, DISABLED_MimeHandler) {
   RunNaClIntegrationTest(FILE_PATH_LITERAL(
       "ppapi_extension_mime_handler.html"));
 }
 
 }  // namespace