Calculator suggestions are responses from the search backend that provide the result of a mathematical expression. For example, if the user types "2 ^ 3" in the omnibox, one of the suggestions shown in the dropdown will be "8". In order to make it clearer that this is the result of the expression, an '=' suggestion-type icon is shown (rather than the magnifying glass icon normally shown for search suggestions).

On phones, however, suggestion-type icons are not displayed. We should instead show '=' as text in front of the result text (e.g. "= 8"). As it happens, this text actually appears in the response from the server. But we added logic to remove it when we introduced the '=' icon:

https://cs.chromium.org/chromium/src/components/omnibox/browser/search_suggestion_parser.cc?l=518-520&rcl=7171bc6ff5be63301e024db28fd44c87e6f7988a

At that time, I believe that the type icons were being displayed on phones. Now that they're not, we should skip removing the '=' text on phones. In other words, that logic above should include an exception on phones.