Android: Fix a crash in navigation sheet

The reported crash can happen when navigation sheet's request to show
fails. It should have always called |hideContent| to remove itself
from the queue but it was done only when the current sheet state is
hidden. This CL fixes it to perform the hiding operation
unconditionally.

Bug: 1021932
Change-Id: I3fa3c08ff814d9aa2aa149196b9f5e91b262cb73
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1910819Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Jinsuk Kim <jinsukkim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714527}

chrome/android/java/src/org/chromium/chrome/browser/gesturenav/NavigationSheetCoordinator.java

@@ -244,9 +244,10 @@ class NavigationSheetCoordinator implements BottomSheetContent, NavigationSheet
 
     @Override
     public void close(boolean animate) {
-        if (mBottomSheetController.get() == null) return;
-        if (!isHidden()) mBottomSheetController.get().hideContent(this, animate);
-        mBottomSheetController.get().removeObserver(mSheetObserver);
+        BottomSheetController controller = mBottomSheetController.get();
+        if (controller == null) return;
+        controller.hideContent(this, animate);
+        controller.removeObserver(mSheetObserver);
         mMediator.clear();
     }