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

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc

Index: chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
diff --git a/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc b/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
index 6171938fa84e34e546df81d74eff5f05c9288ee4..4eca8affbe670aa975dd0cff50dc0c88cf67b553 100644
--- a/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
+++ b/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc
@@ -45,10 +45,7 @@ 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 {
@@ -133,15 +130,13 @@ void RecordLinuxGlibcVersion() {
       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
 }