Use process per site instance for "Instant".

chrome/browser/search/search.cc

 // 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.
 
 #include "chrome/browser/search/search.h"
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
@@ skipping 278 matching lines @@
 }
 
 bool ShouldAssignURLToInstantRenderer(const GURL& url, Profile* profile) {
   return url.is_valid() &&
          profile &&
          IsInstantExtendedAPIEnabled() &&
          (url.SchemeIs(chrome::kChromeSearchScheme) ||
           IsInstantURL(url, profile));
 }
 
+bool ShouldInstantURLUseProcessPerSite(const GURL& url, Profile* profile) {
+  return ShouldAssignURLToInstantRenderer(url, profile) &&
+      (url.host() == chrome::kChromeSearchLocalNtpHost ||
+       url.host() == chrome::kChromeSearchOnlineNtpHost);
+}
+
 bool IsInstantNTP(const content::WebContents* contents) {
   if (!contents)
     return false;
 
   return NavEntryIsInstantNTP(contents,
                               contents->GetController().GetVisibleEntry());
 }
 
 bool NavEntryIsInstantNTP(const content::WebContents* contents,
                           const content::NavigationEntry* entry) {
@@ skipping 241 matching lines @@
                                     bool default_value,
                                     const FieldTrialFlags& flags) {
   return !!GetUInt64ValueForFlagWithDefault(flag, default_value ? 1 : 0, flags);
 }
 
 void ResetInstantExtendedOptInStateGateForTest() {
   instant_extended_opt_in_state_gate = false;
 }
 
 }  // namespace chrome