Remove DetermineIfPageSupportsInstant and all its plumbing

chrome/renderer/searchbox/searchbox.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_RENDERER_SEARCHBOX_SEARCHBOX_H_
 #define CHROME_RENDERER_SEARCHBOX_SEARCHBOX_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 126 matching lines @@
   const InstantSuggestion& suggestion() const { return suggestion_; }
 
  private:
   // Overridden from content::RenderFrameObserver:
   void OnDestruct() override;
 
   // Overridden from chrome::mojom::SearchBox:
   void SetPageSequenceNumber(int page_seq_no) override;
   void ChromeIdentityCheckResult(const base::string16& identity,
                                  bool identity_match) override;
-  void DetermineIfPageSupportsInstant() override;
   void FocusChanged(OmniboxFocusState new_focus_state,
                     OmniboxFocusChangeReason reason) override;
   void HistorySyncCheckResult(bool sync_history) override;
   void MostVisitedChanged(
       const std::vector<InstantMostVisitedItem>& items) override;
   void SetInputInProgress(bool input_in_progress) override;
   void SetSuggestionToPrefetch(const InstantSuggestion& suggestion) override;
   void Submit(const base::string16& query,
               const EmbeddedSearchRequestParams& params) override;
   void ThemeChanged(const ThemeBackgroundInfo& theme_info) override;
@@ skipping 18 matching lines @@
   base::string16 query_;
   EmbeddedSearchRequestParams embedded_search_request_params_;
   InstantSuggestion suggestion_;
   chrome::mojom::InstantAssociatedPtr instant_service_;
   mojo::AssociatedBinding<chrome::mojom::SearchBox> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(SearchBox);
 };
 
 #endif  // CHROME_RENDERER_SEARCHBOX_SEARCHBOX_H_