[iOS] Add space when omnibox suggestion has tab match

This CL makes sure that the omnibox suggestions labels width is taking
into account the presence of the "switch to open tab" button.

Bug: 908874
Change-Id: I92ce30dabadc511a319b43879baa125fa080e0f8
Reviewed-on: https://chromium-review.googlesource.com/c/1353940
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612209}

ios/chrome/browser/ui/omnibox/popup/omnibox_popup_view_controller.mm

@@ -417,12 +417,13 @@ UIColor* BackgroundColorIncognito() {
 
   // Show append button for search history/search suggestions as the right
   // control element (aka an accessory element of a table view cell).
-  row.trailingButton.hidden = !match.isAppendable && !match.isTabMatch;
+  BOOL hasVisibleTrailingButton = match.isAppendable || match.isTabMatch;
+  row.trailingButton.hidden = !hasVisibleTrailingButton;
   [row.trailingButton cancelTrackingWithEvent:nil];
 
   // If a right accessory element is present or the text alignment is right
   // aligned, adjust the width to align with the accessory element.
-  if (match.isAppendable || alignmentRight) {
+  if (hasVisibleTrailingButton || alignmentRight) {
     LayoutRect layout =
         LayoutRectForRectInBoundingRect(textLabel.frame, self.view.frame);
     layout.size.width -= kTrailingButtonWidth;