Add desktop engagement metrics.

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index a93e7fc9b0ab471f5568e8b38c206742dc1db617..a4984e14425727ab6ad70e1802d771aeeebf0605 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -267,6 +267,10 @@
 #include "services/shell/runner/common/client_util.h"
 #endif
 
+#if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
+#include "chrome/browser/metrics/desktop_engagement/desktop_engagement_service.h"
+#endif
+
 using content::BrowserThread;
 
 namespace {
@@ -790,6 +794,11 @@ void ChromeBrowserMainParts::SetupMetricsAndFieldTrials() {
   // that was already chosen.
   sampling_profiler_config_.RegisterSyntheticFieldTrial();
 
+#if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
+  // Start the DesktopEngagementService.
+  DesktopEngagementService::Initialize();
+#endif  // defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
+
 #if defined(OS_WIN)
   chrome_browser::SetupPreReadFieldTrial();
 #endif  // defined(OS_WIN)