Remove search::ShouldPrefetchSearchResultsOnSRP

chrome/browser/ui/omnibox/chrome_omnibox_client.cc

 // 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 "chrome/browser/ui/omnibox/chrome_omnibox_client.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 440 matching lines @@
   }
   // We could prefetch the alternate nav URL, if any, but because there
   // can be many of these as a user types an initial series of characters,
   // the OS DNS cache could suffer eviction problems for minimal gain.
 }
 
 void ChromeOmniboxClient::SetSuggestionToPrefetch(
       const InstantSuggestion& suggestion) {
   DCHECK(search::IsInstantExtendedAPIEnabled());
   content::WebContents* web_contents = controller_->GetWebContents();
-  if (web_contents &&
-      SearchTabHelper::FromWebContents(web_contents)->IsSearchResultsPage()) {
-    if (search::ShouldPrefetchSearchResultsOnSRP()) {
-      SearchTabHelper::FromWebContents(web_contents)->
-          SetSuggestionToPrefetch(suggestion);
-    }
-  } else {
+  if (!web_contents ||
+      !SearchTabHelper::FromWebContents(web_contents)->IsSearchResultsPage()) {

[Marc Treib, 2016/07/29 10:40:14]

I've investigated a bit more, and it seems that IsSearchResultsPage() is always
false here in practice - it checks SearchMode.is_origin_search(), which is never
true:
If we started out on an NTP, it's origin_ntp instead.
If we started on a search page (or anywhere else), then that isn't rendered in
the Instant process, so it's considered to not have instant support, so it's
origin_default instead.

Is this expected? Was the whole special SRP handling abandoned, or is there a
bug somewhere?

     InstantSearchPrerenderer* prerenderer =
         InstantSearchPrerenderer::GetForProfile(profile_);
     if (prerenderer)
       prerenderer->Prerender(suggestion);
   }
 }
 
 void ChromeOmniboxClient::OnBitmapFetched(const BitmapFetchedCallback& callback,
                                           const SkBitmap& bitmap) {
   request_id_ = BitmapFetcherService::REQUEST_ID_INVALID;
   callback.Run(bitmap);
 }