Fix status label constraints for in-progress download.

Use constraintLessThanOrEqualToAnchor: to make sure that close button
always anchored to the right edge of the view.

Bug: None
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Icf2c7064d8172056d1cba02987d703496d2dc25d
Reviewed-on: https://chromium-review.googlesource.com/998348Reviewed-by: edchin <edchin@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548511}

ios/chrome/browser/ui/download/download_manager_view_controller.mm

@@ -633,8 +633,8 @@ NSString* GetSizeString(long long size_in_bytes) {
                                     : self.actionButton;
 
   self.statusLabelTrailingConstraint = [self.statusLabel.trailingAnchor
-      constraintEqualToAnchor:secondAnchorElement.leadingAnchor
-                     constant:-kElementMargin];
+      constraintLessThanOrEqualToAnchor:secondAnchorElement.leadingAnchor
+                               constant:-kElementMargin];
 
   self.statusLabelTrailingConstraint.active = YES;
 }