Add a null check to ChromeActivity#onStartWithNative()

chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
index 27a4b69429a6153bc62daaa7405debd4de5c9f65..ec634afa787f304b70325fcfc956387efc71df2a 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java
@@ -583,7 +583,7 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
         // #onPageLoadFinished() and #onCrash(). If we are not actively loading a tab (e.g.
         // in Android N multi-instance, which is created by re-parenting an existing tab),
         // ensure onDeferredStartup() gets called by calling postDeferredStartupIfNeeded() here.
-        if (!getActivityTab().isLoading()) {
+        if (getActivityTab() == null || !getActivityTab().isLoading()) {
             postDeferredStartupIfNeeded();
         }
     }