Record NTP.LogoShownTime for timely refreshs only

chrome/browser/android/logo_bridge.h

Index: chrome/browser/android/logo_bridge.h
diff --git a/chrome/browser/android/logo_bridge.h b/chrome/browser/android/logo_bridge.h
index 89f5f48b12a3ecf1dbc0e09e08098b45d4aee407..99ce2babc472602497a5d27113d25955f22e90ef 100644
--- a/chrome/browser/android/logo_bridge.h
+++ b/chrome/browser/android/logo_bridge.h
@@ -38,8 +38,13 @@ class LogoBridge : public doodle::DoodleService::Observer {
   explicit LogoBridge(jobject j_profile);
   void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
 
+  // TODO(treib): Double-check the observer contract (esp. for LogoTracker).
   // Gets the current non-animated logo (downloading it if necessary) and passes
   // it to the observer.
+  // The observer's |onLogoAvailable| is guaranteed to be called at least once:
+  // a) A cached doodle is available.
+  // b) A new doodle is available.
+  // c) Not having a doodle was revalidated.
   void GetCurrentLogo(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj,
@@ -60,13 +65,13 @@ class LogoBridge : public doodle::DoodleService::Observer {
   virtual ~LogoBridge();
 
   // doodle::DoodleService::Observer implementation.
+  void OnDoodleConfigRevalidated(bool from_cache) override;
   void OnDoodleConfigUpdated(
       const base::Optional<doodle::DoodleConfig>& maybe_doodle_config) override;
 
-  void DoodleConfigReceived(
-      const base::Optional<doodle::DoodleConfig>& maybe_doodle_config,
-      bool from_cache);
-
+  void NotifyNoLogoAvailable(bool from_cache);
+  void FetchDoodleImage(const doodle::DoodleConfig& doodle_config,
+                        bool from_cache);
   void DoodleImageFetched(bool config_from_cache,
                           const GURL& on_click_url,
                           const std::string& alt_text,