Record histograms for on-demand update check results.

chrome/browser/google/google_update_win.cc

Index: chrome/browser/google/google_update_win.cc
diff --git a/chrome/browser/google/google_update_win.cc b/chrome/browser/google/google_update_win.cc
index 0b217ad76bc3d4b39fde9ecf4b7b957815fd73a2..83b2a1081733c44c2eb48c95f372c0bc0fd4d77e 100644
--- a/chrome/browser/google/google_update_win.cc
+++ b/chrome/browser/google/google_update_win.cc
@@ -10,6 +10,8 @@
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/sparse_histogram.h"
 #include "base/path_service.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ -391,6 +393,12 @@ void GoogleUpdate::ReportResults(GoogleUpdateUpgradeResult results,
   // If there is an error, then error code must not be blank, and vice versa.
   DCHECK(results == UPGRADE_ERROR ? error_code != GOOGLE_UPDATE_NO_ERROR :
                                     error_code == GOOGLE_UPDATE_NO_ERROR);
+  UMA_HISTOGRAM_ENUMERATION(
+      "UpdateCheckWin.UpgradeResult", results, NUM_UPGRADE_RESULTS);

[Alexei Svitkine (slow), 2014/10/17 19:00:55]

Can you use the existing GoogleUpdate. prefix instead of introducing a new one
top-level one?

[grt (UTC plus 2), 2014/10/18 02:37:34]

Done.

+  if (results == UPGRADE_ERROR) {
+    UMA_HISTOGRAM_ENUMERATION(
+        "UpdateCheckWin.UpdateErrorCode", error_code, NUM_ERROR_CODES);
+  }
   if (listener_) {
     listener_->OnReportResults(
         results, error_code, error_message, version_available_);
@@ -404,6 +412,7 @@ bool GoogleUpdate::ReportFailure(HRESULT hr,
   DLOG(ERROR) << "Communication with Google Update failed: " << hr
               << " error: " << error_code
               << ", message: " << error_message.c_str();
+  UMA_HISTOGRAM_SPARSE_SLOWLY("UpdateCheckWin.ErrorHresult", hr);
   main_loop->PostTask(
       FROM_HERE,
       base::Bind(&GoogleUpdate::ReportResults, this,