Init WebApkUpdateManager with a WebappDataStorage to avoid null object.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
index b7193081807ff80f6c27fa622392c7b5ffa33a5b..cf0db4622bc2d0101fe544962f2040baca39c5a0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
@@ -294,6 +294,27 @@ public class WebappActivity extends FullScreenActivity {
     }
 
     @Override
+    public void onDeferredStartup() {
+        super.onDeferredStartup();
+
+        WebappDataStorage storage =
+                WebappRegistry.getInstance().getWebappDataStorage(mWebappInfo.id());
+        if (storage != null) {
+            onDeferredStartupWithStorage(storage);
+        } else {
+            onDeferredStartupWithNullStorage();
+        }
+    }
+
+    protected void onDeferredStartupWithStorage(WebappDataStorage storage) {
+        updateStorage(storage);
+    }
+
+    protected void onDeferredStartupWithNullStorage() {
+        return;
+    }
+
+    @Override
     protected int getControlContainerLayoutId() {
         return R.layout.webapp_control_container;
     }
@@ -348,11 +369,10 @@ public class WebappActivity extends FullScreenActivity {
         WebappDataStorage storage =
                 WebappRegistry.getInstance().getWebappDataStorage(mWebappInfo.id());
         if (storage == null) {
-            onStorageIsNull(backgroundColor);
+            initializeSplashScreenWidgets(backgroundColor, null);
             return;
         }
 
-        updateStorage(storage);
         storage.getSplashScreenImage(new WebappDataStorage.FetchCallback<Bitmap>() {
             @Override
             public void onDataRetrieved(Bitmap splashImage) {
@@ -361,8 +381,6 @@ public class WebappActivity extends FullScreenActivity {
         });
     }
 
-    protected void onStorageIsNull(int backgroundColor) {}
-
     protected void updateStorage(WebappDataStorage storage) {
         // The information in the WebappDataStorage may have been purged by the
         // user clearing their history or not launching the web app recently.