Remove search::GetSearchTerms since it always returns empty string

chrome/browser/ui/toolbar/chrome_toolbar_model_delegate.h

 // Copyright 2016 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_BROWSER_UI_TOOLBAR_CHROME_TOOLBAR_MODEL_DELEGATE_H_
 #define CHROME_BROWSER_UI_TOOLBAR_CHROME_TOOLBAR_MODEL_DELEGATE_H_
 
 #include "base/macros.h"
 #include "components/toolbar/toolbar_model_delegate.h"
 
@@ skipping 16 matching lines @@
   ChromeToolbarModelDelegate();
   ~ChromeToolbarModelDelegate() override;
 
  private:
   base::string16 FormattedStringWithEquivalentMeaning(
       const GURL& url,
       const base::string16& formatted_url) const override;
   bool GetURL(GURL* url) const override;
   bool ShouldDisplayURL() const override;
   SecurityLevel GetSecurityLevel() const override;
-  base::string16 GetSearchTerms(SecurityLevel security_level) const override;
   scoped_refptr<net::X509Certificate> GetCertificate() const override;
 
   // Returns the navigation controller used to retrieve the navigation entry
   // from which the states are retrieved. If this returns null, default values
   // are used.
   content::NavigationController* GetNavigationController() const;
 
   // Helper method to extract the navigation entry from the navigation
   // controller.
   content::NavigationEntry* GetNavigationEntry() const;
 
   // Helper method to extract the profile from the navigation controller.
   Profile* GetProfile() const;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeToolbarModelDelegate);
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_CHROME_TOOLBAR_MODEL_DELEGATE_H_