[omnibox] Break out SetCaretPos() method and enhance browser test

components/omnibox/browser/omnibox_edit_unittest.cc

 // Copyright (c) 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.
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 31 matching lines @@
   void SetUserText(const base::string16& text,
                    bool update_popup) override {
     text_ = text;
   }
   void SetWindowTextAndCaretPos(const base::string16& text,
                                 size_t caret_pos,
                                 bool update_popup,
                                 bool notify_text_changed) override {
     text_ = text;
   }
+  void SetCaretPos(size_t caret_pos) override {}
   void EnterKeywordModeForDefaultSearchProvider() override {}
   bool IsSelectAll() const override { return false; }
   bool DeleteAtEndPressed() override { return false; }
   void GetSelectionBounds(size_t* start, size_t* end) const override {}
   void SelectAll(bool reversed) override {}
   void RevertAll() override {}
   void UpdatePopup() override {}
   void SetFocus() override {}
   void ApplyCaretVisibility() override {}
   void OnTemporaryTextMaybeChanged(const base::string16& display_text,
@@ skipping 279 matching lines @@
                      alternate_nav_url, base::string16(), 0);
   EXPECT_TRUE(AutocompleteInput::HasHTTPScheme(
       client->alternate_nav_match().fill_into_edit));
 
   model()->SetUserText(base::ASCIIToUTF16("abcd"));
   model()->OpenMatch(match, WindowOpenDisposition::CURRENT_TAB,
                      alternate_nav_url, base::string16(), 0);
   EXPECT_TRUE(AutocompleteInput::HasHTTPScheme(
       client->alternate_nav_match().fill_into_edit));
 }