Make const versions GetTemplateURLForKeyword, GetTemplateURLForGUID, GetTemplateURLForHost

ios/chrome/browser/ui/omnibox/chrome_omnibox_client_ios.mm

 // Copyright 2013 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.
 
 #include "ios/chrome/browser/ui/omnibox/chrome_omnibox_client_ios.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/favicon/ios/web_favicon_driver.h"
 #include "components/omnibox/browser/omnibox_edit_controller.h"
@@ skipping 105 matching lines @@
   return ios::AutocompleteClassifierFactory::GetForBrowserState(browser_state_);
 }
 
 gfx::Image ChromeOmniboxClientIOS::GetIconIfExtensionMatch(
     const AutocompleteMatch& match) const {
   // Extensions are not supported on iOS.
   return gfx::Image();
 }
 
 bool ChromeOmniboxClientIOS::ProcessExtensionKeyword(
-    TemplateURL* template_url,
+    const TemplateURL* template_url,
     const AutocompleteMatch& match,
     WindowOpenDisposition disposition,
     OmniboxNavigationObserver* observer) {
   // Extensions are not supported on iOS.
   return false;
 }
 
 void ChromeOmniboxClientIOS::OnInputStateChanged() {}
 
 void ChromeOmniboxClientIOS::OnFocusChanged(OmniboxFocusState state,
@@ skipping 31 matching lines @@
     const AutocompleteMatch& current_match,
     bool user_input_in_progress,
     base::string16& user_text,
     const AutocompleteResult& result,
     bool is_popup_open,
     bool has_focus) {}
 
 void ChromeOmniboxClientIOS::OnInputAccepted(const AutocompleteMatch& match) {}
 
 void ChromeOmniboxClientIOS::OnRevert() {}