[Offline indicator v2] Clean up the animations on destroy

Currently, if the status indicator is destroyed while there are running
animations, we still get an #onAnimationEnd call causing NPEs.

To prevent this, this CL cancels all animations in #destroy(). Also, it
adds some null checks in TabbedRootUiCoordinator where we can
potentially try to access null mActivity and ActivityTabProvider.

Bug: 1087010
Change-Id: I60a199cdebad160b2ef3f63719552cc54cce87a3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2219348Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Sinan Sahin <sinansahin@google.com>
Cr-Commit-Position: refs/heads/master@{#772934}

chrome/android/java/src/org/chromium/chrome/browser/status_indicator/StatusIndicatorCoordinator.java

@@ -96,6 +96,7 @@ public class StatusIndicatorCoordinator {
 
     public void destroy() {
         mRemoveOnLayoutChangeListener.run();
+        mMediator.destroy();
     }
 
     // TODO(sinansahin): Destroy the view when not needed.

chrome/android/java/src/org/chromium/chrome/browser/tabbed_mode/TabbedRootUiCoordinator.java

@@ -97,6 +97,9 @@ public class TabbedRootUiCoordinator extends RootUiCoordinator implements Native
         mIntentWithEffect = intentWithEffect;
         mEphemeralTabCoordinatorSupplier = ephemeralTabCoordinatorSupplier;
         mCanAnimateBrowserControls = () -> {
+            // These null checks prevent any exceptions that may be caused by callbacks after
+            // destruction.
+            if (mActivity == null || mActivity.getActivityTabProvider() == null) return false;
             final Tab tab = mActivity.getActivityTabProvider().get();
             return tab != null && tab.isUserInteractable() && !tab.isNativePage();
         };