Remove DetermineIfPageSupportsInstant and all its plumbing

chrome/renderer/searchbox/searchbox_extension.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_EXTENSION_H_
 #define CHROME_RENDERER_SEARCHBOX_SEARCHBOX_EXTENSION_H_
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 
 namespace v8 {
 class Extension;
 }
 
 namespace blink {
 class WebFrame;
 }
 
 namespace extensions_v8 {
 
 // Reference implementation of the SearchBox API as described in:
 // http://dev.chromium.org/searchbox
 class SearchBoxExtension {
  public:
   // Returns the v8::Extension object handling searchbox bindings. Returns null
   // if match-preview is not enabled. Caller takes ownership of returned object.
   static v8::Extension* Get();
 
-  // Returns true if a page supports Instant, that is, if it has bound an
-  // onsubmit() handler.
-  static bool PageSupportsInstant(blink::WebFrame* frame);
-
   // Helpers to dispatch Javascript events.
   static void DispatchChromeIdentityCheckResult(blink::WebFrame* frame,
                                                 const base::string16& identity,
                                                 bool identity_match);
   static void DispatchFocusChange(blink::WebFrame* frame);
   static void DispatchHistorySyncCheckResult(blink::WebFrame* frame,
                                              bool sync_history);
   static void DispatchInputCancel(blink::WebFrame* frame);
   static void DispatchInputStart(blink::WebFrame* frame);
   static void DispatchKeyCaptureChange(blink::WebFrame* frame);
   static void DispatchMostVisitedChanged(blink::WebFrame* frame);
   static void DispatchSubmit(blink::WebFrame* frame);
   static void DispatchSuggestionChange(blink::WebFrame* frame);
   static void DispatchThemeChange(blink::WebFrame* frame);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(SearchBoxExtension);
 };
 
 }  // namespace extensions_v8
 
 #endif  // CHROME_RENDERER_SEARCHBOX_SEARCHBOX_EXTENSION_H_