Fix tab presentation metrics

ios/chrome/browser/ui/browser_view_controller.mm

Index: ios/chrome/browser/ui/browser_view_controller.mm
diff --git a/ios/chrome/browser/ui/browser_view_controller.mm b/ios/chrome/browser/ui/browser_view_controller.mm
index 1beacd5bfcf280a37bc1afa71678e7b0c02942bd..e7b12f656e8b54507f709484da1928be5cdc2d6a 100644
--- a/ios/chrome/browser/ui/browser_view_controller.mm
+++ b/ios/chrome/browser/ui/browser_view_controller.mm
@@ -1639,6 +1639,7 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
 
           if (self.foregroundTabWasAddedCompletionBlock) {
             self.foregroundTabWasAddedCompletionBlock();
+            self.foregroundTabWasAddedCompletionBlock = nil;
           }
         });
   } else {
@@ -1677,10 +1678,11 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
             [topTab updateSnapshotWithOverlay:YES visibleFrameOnly:YES];
           startVoiceSearchIfNecessaryBlock();
         });
+    // Reset the foreground tab completion block so that it can never be
+    // called more than once regardless of foreground/background tab
+    // appearances.
+    self.foregroundTabWasAddedCompletionBlock = nil;
   }
-  // Reset the foreground tab completion block so that it can never be
-  // called more than once regardless of foreground/background tab appearances.
-  self.foregroundTabWasAddedCompletionBlock = nil;
 }
 
 #pragma mark - UI Configuration and Layout