[NTP Client] Make the SignInPromo update on SignInAllowed changes

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
index 2aa48dd80488fd03a9167136cffb42b358bfe0fd..1dd1f88fcbb12c43167aee7c0d4faad2a257a07f 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
@@ -49,6 +49,7 @@
 import org.chromium.chrome.browser.ntp.LogoBridge.LogoObserver;
 import org.chromium.chrome.browser.ntp.MostVisitedItem.MostVisitedItemManager;
 import org.chromium.chrome.browser.ntp.NewTabPage.OnSearchBoxScrollListener;
+import org.chromium.chrome.browser.ntp.NewTabPage.SelfRegistrable;
 import org.chromium.chrome.browser.ntp.cards.CardsVariationParameters;
 import org.chromium.chrome.browser.ntp.cards.NewTabPageAdapter;
 import org.chromium.chrome.browser.ntp.cards.NewTabPageRecyclerView;
@@ -56,7 +57,6 @@
 import org.chromium.chrome.browser.ntp.snippets.SnippetsConfig;
 import org.chromium.chrome.browser.ntp.snippets.SuggestionsSource;
 import org.chromium.chrome.browser.profiles.MostVisitedSites.MostVisitedURLsObserver;
-import org.chromium.chrome.browser.signin.SigninManager.SignInStateObserver;
 import org.chromium.chrome.browser.util.MathUtils;
 import org.chromium.chrome.browser.util.ViewUtils;
 import org.chromium.chrome.browser.widget.RoundedIconGenerator;
@@ -295,10 +295,12 @@ void ensureIconIsAvailable(String pageUrl, String iconUrl, boolean isLargeIcon,
         @Nullable SuggestionsSource getSuggestionsSource();
 
         /**
-         * Registers a {@link SignInStateObserver}, will handle the de-registration when the New Tab
-         * Page goes away.
+         * Registers a {@link SelfRegistrable}, will be registered right away and unregistered when
+         * when the New Tab Page goes away.
+         * TODO(dgn): This currently supports setting only one. Extend add them to a lists if

[Michael van Ouwerkerk, 2016/10/19 12:09:18]

Then maybe call it "set" instead of "add" for the moment? Then you don't need
this TODO either.

[dgn, 2016/10/19 17:03:41]

Done.

+         * needed somewhere else.

[Bernhard Bauer, 2016/10/19 12:15:27]

Yeah, I would maybe call the method set...

[dgn, 2016/10/19 17:03:41]

Done.

          */
-        void registerSignInStateObserver(SignInStateObserver signInStateObserver);
+        void addSelfRegistrable(SelfRegistrable selfRegistrable);
 
         /**
          * @return whether the {@link NewTabPage} associated with this manager is the current page