Update the Linux.GlibcVersion histogram to handle glibc 2.2x.

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc

 // Copyright (c) 2013 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 "chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 27 matching lines @@
 #if defined(OS_WIN)
 #include "chrome/installer/util/google_update_settings.h"
 #endif  // defined(OS_WIN)
 
 namespace {
 
 enum UMALinuxGlibcVersion {
   UMA_LINUX_GLIBC_NOT_PARSEABLE,
   UMA_LINUX_GLIBC_UNKNOWN,
   UMA_LINUX_GLIBC_2_11,
-  UMA_LINUX_GLIBC_2_19 = UMA_LINUX_GLIBC_2_11 + 8,
-  // NOTE: Add new version above this line and update the enum list in
-  // tools/metrics/histograms/histograms.xml accordingly.
-  UMA_LINUX_GLIBC_VERSION_COUNT
+  // To log newer versions, just update tools/metrics/histograms/histograms.xml.
 };
 
 enum UMALinuxWindowManager {
   UMA_LINUX_WINDOW_MANAGER_OTHER,
   UMA_LINUX_WINDOW_MANAGER_BLACKBOX,
   UMA_LINUX_WINDOW_MANAGER_CHROME_OS,  // Deprecated.
   UMA_LINUX_WINDOW_MANAGER_COMPIZ,
   UMA_LINUX_WINDOW_MANAGER_ENLIGHTENMENT,
   UMA_LINUX_WINDOW_MANAGER_ICE_WM,
   UMA_LINUX_WINDOW_MANAGER_KWIN,
@@ skipping 64 matching lines @@
   if (version.IsValid() && version.components().size() == 2) {
     glibc_version_result = UMA_LINUX_GLIBC_UNKNOWN;
     int glibc_major_version = version.components()[0];
     int glibc_minor_version = version.components()[1];
     if (glibc_major_version == 2) {
       // A constant to translate glibc 2.x minor versions to their
       // equivalent UMALinuxGlibcVersion values.
       const int kGlibcMinorVersionTranslationOffset = 11 - UMA_LINUX_GLIBC_2_11;
       int translated_glibc_minor_version =
           glibc_minor_version - kGlibcMinorVersionTranslationOffset;
-      if (translated_glibc_minor_version >= UMA_LINUX_GLIBC_2_11 &&
-          translated_glibc_minor_version <= UMA_LINUX_GLIBC_2_19) {
+      if (translated_glibc_minor_version >= UMA_LINUX_GLIBC_2_11) {
         glibc_version_result =
             static_cast<UMALinuxGlibcVersion>(translated_glibc_minor_version);
       }
     }
   }
-  UMA_HISTOGRAM_ENUMERATION("Linux.GlibcVersion", glibc_version_result,
-                            UMA_LINUX_GLIBC_VERSION_COUNT);
+  UMA_HISTOGRAM_SPARSE_SLOWLY("Linux.GlibcVersion", glibc_version_result);
 #endif
 }
 
 #if defined(USE_X11) && !defined(OS_CHROMEOS)
 UMALinuxWindowManager GetLinuxWindowManager() {
   switch (ui::GuessWindowManager()) {
     case ui::WM_UNKNOWN:
       return UMA_LINUX_WINDOW_MANAGER_OTHER;
     case ui::WM_AWESOME:
       return UMA_LINUX_WINDOW_MANAGER_AWESOME;
@@ skipping 144 matching lines @@
   }
 }
 
 namespace chrome {
 
 void AddMetricsExtraParts(ChromeBrowserMainParts* main_parts) {
   main_parts->AddParts(new ChromeBrowserMainExtraPartsMetrics());
 }
 
 }  // namespace chrome