Renumber base::win::Version and stop emitting histograms based on it.

Add missing WIN10_19H2 entry, and update tests.

BUG=1130738

Change-Id: Ia9208cebdd092c084468bf31482907afe56a4ef3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2458328
Auto-Submit: Will Harris <wfh@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
Commit-Queue: Mark Pearson <mpearson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816845}

base/win/windows_version.cc

@@ -258,6 +258,8 @@ Version OSInfo::MajorMinorBuildToVersion(int major, int minor, int build) {
   if (major == 10) {
     if (build >= 19041)
       return Version::WIN10_20H1;
+    if (build >= 18363)
+      return Version::WIN10_19H2;
     if (build >= 18362)
       return Version::WIN10_19H1;
     if (build >= 17763)

base/win/windows_version.h

@@ -31,9 +31,6 @@ namespace win {
 // syntactic sugar reasons; see the declaration of GetVersion() below.
 // NOTE: Keep these in order so callers can do things like
 // "if (base::win::GetVersion() >= base::win::Version::VISTA) ...".
-//
-// This enum is used in metrics histograms, so they shouldn't be reordered or
-// removed. New values can be added before Version::WIN_LAST.
 enum class Version {
   PRE_XP = 0,  // Not supported.
   XP = 1,
@@ -50,10 +47,9 @@ enum class Version {
   WIN10_RS4 = 12,   // Redstone 4: Version 1803, Build 17134.
   WIN10_RS5 = 13,   // Redstone 5: Version 1809, Build 17763.
   WIN10_19H1 = 14,  // 19H1: Version 1903, Build 18362.
-  WIN10_20H1 = 15,  // 20H1: Version 2004, Build 19041.
-  // On edit, update tools\metrics\histograms\enums.xml "WindowsVersion" and
-  // "GpuBlacklistFeatureTestResultsWindows2".
-  WIN_LAST,  // Indicates error condition.
+  WIN10_19H2 = 15,  // 19H2: Version 1909, Build 18363.
+  WIN10_20H1 = 16,  // 20H1: Version 2004, Build 19041.
+  WIN_LAST,         // Indicates error condition.
 };
 
 // A rough bucketing of the available types of versions of Windows. This is used

base/win/windows_version_unittest.cc

@@ -10,11 +10,16 @@
 namespace base {
 namespace win {
 
-TEST(WindowsVersion, GetVersionExAndKernelVersionMatch) {
+TEST(WindowsVersion, GetVersionExAndKernelOsVersionMatch) {
   // If this fails, we're running in compatibility mode, or need to update the
   // application manifest.
-  EXPECT_EQ(OSInfo::GetInstance()->version(),
-            OSInfo::GetInstance()->Kernel32Version());
+  // Note: not all versions of Windows return identical build numbers e.g.
+  // 1909/19H2 kernel32.dll has build number 18362 but OS version build number
+  // 18363.
+  EXPECT_EQ(OSInfo::GetInstance()->Kernel32VersionNumber().major,
+            OSInfo::GetInstance()->version_number().major);
+  EXPECT_EQ(OSInfo::GetInstance()->Kernel32VersionNumber().minor,
+            OSInfo::GetInstance()->version_number().minor);
 }
 
 TEST(OSInfo, MajorMinorBuildToVersion) {
@@ -22,6 +27,8 @@ TEST(OSInfo, MajorMinorBuildToVersion) {
             Version::WIN10_20H1);
   EXPECT_EQ(OSInfo::MajorMinorBuildToVersion(10, 0, 19041),
             Version::WIN10_20H1);
+  EXPECT_EQ(OSInfo::MajorMinorBuildToVersion(10, 0, 18363),
+            Version::WIN10_19H2);
   EXPECT_EQ(OSInfo::MajorMinorBuildToVersion(10, 0, 18362),
             Version::WIN10_19H1);
   EXPECT_EQ(OSInfo::MajorMinorBuildToVersion(10, 0, 17763), Version::WIN10_RS5);

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc

@@ -152,12 +152,6 @@ bool IsApplockerRunning();
 void RecordStartupMetrics() {
 #if defined(OS_WIN)
   const base::win::OSInfo& os_info = *base::win::OSInfo::GetInstance();
-  base::UmaHistogramEnumeration("Windows.GetVersionExVersion",
-                                os_info.version(),
-                                base::win::Version::WIN_LAST);
-  base::UmaHistogramEnumeration("Windows.Kernel32Version",
-                                os_info.Kernel32Version(),
-                                base::win::Version::WIN_LAST);
   int patch = os_info.version_number().patch;
   int build = os_info.version_number().build;
   int patch_level = 0;

tools/metrics/histograms/enums.xml

@@ -78230,6 +78230,9 @@ Called by update_scheduler_enums.py.-->
 </enum>
 
 <enum name="WindowsVersion">
+  <obsolete>
+    Removed from code Oct 2020.
+  </obsolete>
   <int value="0" label="Pre-XP"/>
   <int value="1" label="XP"/>
   <int value="2" label="2003 Server"/>
@@ -78244,7 +78247,7 @@ Called by update_scheduler_enums.py.-->
   <int value="11" label="Windows 10 RS3"/>
   <int value="12" label="Windows 10 RS4"/>
   <int value="13" label="Windows 10 RS5"/>
-  <int value="14" label="Windows 10 19H1"/>
+  <int value="14" label="Windows 10 19H1 or 19H2"/>
   <int value="15" label="Windows 10 20H1"/>
 </enum>
 

tools/metrics/histograms/histograms_xml/windows/histograms.xml

@@ -60,6 +60,10 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Windows.GetVersionExVersion" enum="WindowsVersion"
     expires_after="never">
+  <obsolete>
+    Removed 10/2020 as this histogram has been replaced by the synthetic
+    histogram Windows.WindowsVersion generated from Windows.PatchLevel.
+  </obsolete>
 <!-- expires-never: Needed to measure Windows ecosystem. -->
 
   <owner>wfh@chromium.org</owner>
@@ -149,6 +153,11 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Windows.Kernel32Version" enum="WindowsVersion"
     expires_after="never">
+  <obsolete>
+    Removed 10/2020 as this histogram has been replaced by the synthetic
+    histogram Windows.WindowsVersionKernel32 generated from
+    Windows.PatchLevelKernel32.
+  </obsolete>
 <!-- expires-never: Needed to measure Windows ecosystem. -->
 
   <owner>wfh@chromium.org</owner>