Added prerendering to omnibox.

chrome/browser/autocomplete/autocomplete_edit.cc

 // Copyright (c) 2011 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/autocomplete/autocomplete_edit.h"
 
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
 #include "chrome/browser/autocomplete/autocomplete_popup_model.h"
 #include "chrome/browser/autocomplete/autocomplete_popup_view.h"
 #include "chrome/browser/autocomplete/keyword_provider.h"
 #include "chrome/browser/autocomplete/search_provider.h"
 #include "chrome/browser/command_updater.h"
 #include "chrome/browser/extensions/extension_omnibox_api.h"
 #include "chrome/browser/google/google_url_tracker.h"
 #include "chrome/browser/instant/instant_controller.h"
 #include "chrome/browser/net/predictor_api.h"
 #include "chrome/browser/net/url_fixer_upper.h"
+#include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search_engines/template_url.h"
 #include "chrome/browser/search_engines/template_url_service.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/omnibox/omnibox_view.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "content/browser/user_metrics.h"
 #include "content/common/notification_service.h"
 #include "googleurl/src/gurl.h"
 #include "googleurl/src/url_util.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 // AutocompleteEditController
 
@@ skipping 172 matching lines @@
   bool might_support_instant = false;
   if (update_instant_ && instant && tab) {
     if (user_input_in_progress() && popup_->IsOpen()) {
       AutocompleteMatch current_match = CurrentMatch();
       if (current_match.destination_url == PermanentURL()) {
         // The destination is the same as the current url. This typically
         // happens if the user presses the down error in the omnibox, in which
         // case we don't want to load a preview.
         instant->DestroyPreviewContentsAndLeaveActive();
       } else {
-        instant->Update(tab, CurrentMatch(), view_->GetText(),
+        instant->Update(tab, current_match, view_->GetText(),
                         UseVerbatimInstant(), &suggested_text);
       }
     } else {
       instant->DestroyPreviewContents();
     }
     might_support_instant = instant->MightSupportInstant();
+  } else if (tab && tab->tab_contents()) {
+    // Start Prerender of this page instead.
+    CommandLine* cl = CommandLine::ForCurrentProcess();
+    if (cl->HasSwitch(switches::kPrerenderFromOmnibox)) {
+      prerender::PrerenderManager* prerender_manager =
+          tab->tab_contents()->profile()->GetPrerenderManager();
+      if (prerender_manager) {
+        prerender_manager->AddPrerenderWithNoTag(

[sky, 2011/06/20 18:15:54]

Is this cumulative? Meaning might I end up preloading a page for each unique url
generated as I'm typing? Is there any throttling?

[cbentzel, 2011/06/20 18:28:59]

There is throttling in the PrerenderManager code - a 500ms gap between
prerenders is enforced

[dominich, 2011/06/20 18:40:00]

There is a rate limiter that will kick in that only allows for one prerender
every X ms. I've also added the same check as you do above for
user_input_in_progress() and popup_->IsOpen().

+            CurrentMatch().destination_url);

[cbentzel, 2011/06/20 18:06:01]

What is the likelihood that users will choose CurrentMatch()? Do we retain
per-browser-stats, or at least have aggregate stats?

[dominich, 2011/06/20 18:40:00]

It doesn't look like we have any statistics on how often we predict correctly as
it hasn't really been a concern for the suggestion box.

+      }
+    }
   }
 
   if (!might_support_instant) {
     // Hide any suggestions we might be showing.
     view_->SetInstantSuggestion(string16(), false);
 
     // No need to wait any longer for instant.
     FinalizeInstantQuery(string16(), string16(), false);
   } else {
     SetSuggestedText(suggested_text, instant_complete_behavior_);
@@ skipping 771 matching lines @@
 //  static
 bool AutocompleteEditModel::IsSpaceCharForAcceptingKeyword(wchar_t c) {
   switch (c) {
     case 0x0020:  // Space
     case 0x3000:  // Ideographic Space
       return true;
     default:
       return false;
   }
 }