Log some information about the state of the homepage on Android.

chrome/browser/prefs/pref_metrics_service.h

Index: chrome/browser/prefs/pref_metrics_service.h
diff --git a/chrome/browser/prefs/pref_metrics_service.h b/chrome/browser/prefs/pref_metrics_service.h
index 7627e48b4d2f1f8418afe2f7868fd46a7d6860b4..6e61bb536b58831572fc140a86f6bbb2362a885a 100644
--- a/chrome/browser/prefs/pref_metrics_service.h
+++ b/chrome/browser/prefs/pref_metrics_service.h
@@ -25,6 +25,11 @@ class PrefMetricsService : public KeyedService {
   explicit PrefMetricsService(Profile* profile);
   ~PrefMetricsService() override;
 
+  // Records metrics about the state of the homepage on launch.
+  static void RecordHomePageLaunchMetrics(bool show_home_button,
+                                          bool homepage_is_ntp,
+                                          const GURL& homepage_url);
+
   class Factory : public BrowserContextKeyedServiceFactory {
    public:
     static Factory* GetInstance();