chrome/browser/ui/search/search_tab_helper.cc

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/ui/search/search_tab_helper.h"
   6
   7 #include <set>
   8
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/metrics/histogram.h"
  11 #include "base/strings/string16.h"
  12 #include "base/strings/string_util.h"
  13 #include "build/build_config.h"
  14 #include "chrome/browser/history/most_visited_tiles_experiment.h"
  15 #include "chrome/browser/history/top_sites.h"
  16 #include "chrome/browser/profiles/profile.h"
  17 #include "chrome/browser/search/instant_service.h"
  18 #include "chrome/browser/search/instant_service_factory.h"
  19 #include "chrome/browser/search/search.h"
  20 #include "chrome/browser/signin/signin_manager.h"
  21 #include "chrome/browser/signin/signin_manager_factory.h"
  22 #include "chrome/browser/ui/app_list/app_list_util.h"
  23 #include "chrome/browser/ui/browser.h"
  24 #include "chrome/browser/ui/browser_finder.h"
  25 #include "chrome/browser/ui/browser_navigator.h"
  26 #include "chrome/browser/ui/browser_window.h"
  27 #include "chrome/browser/ui/omnibox/location_bar.h"
  28 #include "chrome/browser/ui/omnibox/omnibox_edit_model.h"
  29 #include "chrome/browser/ui/omnibox/omnibox_popup_model.h"
  30 #include "chrome/browser/ui/omnibox/omnibox_view.h"
  31 #include "chrome/browser/ui/search/search_ipc_router_policy_impl.h"
  32 #include "chrome/browser/ui/tab_contents/core_tab_helper.h"
  33 #include "chrome/browser/ui/tabs/tab_strip_model.h"
  34 #include "chrome/browser/ui/tabs/tab_strip_model_utils.h"
  35 #include "chrome/browser/ui/webui/ntp/ntp_user_data_logger.h"
  36 #include "chrome/common/url_constants.h"
  37 #include "content/public/browser/navigation_controller.h"
  38 #include "content/public/browser/navigation_details.h"
  39 #include "content/public/browser/navigation_entry.h"
  40 #include "content/public/browser/navigation_type.h"
  41 #include "content/public/browser/render_process_host.h"
  42 #include "content/public/browser/user_metrics.h"
  43 #include "content/public/browser/web_contents.h"
  44 #include "content/public/browser/web_contents_view.h"
  45 #include "content/public/common/page_transition_types.h"
  46 #include "content/public/common/referrer.h"
  47 #include "grit/generated_resources.h"
  48 #include "net/base/net_errors.h"
  49 #include "ui/base/l10n/l10n_util.h"
  50 #include "url/gurl.h"
  51
  52 DEFINE_WEB_CONTENTS_USER_DATA_KEY(SearchTabHelper);
  53
  54 namespace {
  55
  56 // For reporting Cacheable NTP navigations.
  57 enum CacheableNTPLoad {
  58   CACHEABLE_NTP_LOAD_FAILED = 0,
  59   CACHEABLE_NTP_LOAD_SUCCEEDED = 1,
  60   CACHEABLE_NTP_LOAD_MAX = 2
  61 };
  62
  63 void RecordCacheableNTPLoadHistogram(bool succeeded) {
  64   UMA_HISTOGRAM_ENUMERATION("InstantExtended.CacheableNTPLoad",
  65                             succeeded ? CACHEABLE_NTP_LOAD_SUCCEEDED :
  66                                 CACHEABLE_NTP_LOAD_FAILED,
  67                             CACHEABLE_NTP_LOAD_MAX);
  68 }
  69
  70 bool IsCacheableNTP(const content::WebContents* contents) {
  71   const content::NavigationEntry* entry =
  72       contents->GetController().GetLastCommittedEntry();
  73   return chrome::NavEntryIsInstantNTP(contents, entry) &&
  74       entry->GetURL() != GURL(chrome::kChromeSearchLocalNtpUrl);
  75 }
  76
  77 bool IsNTP(const content::WebContents* contents) {
  78   // We can't use WebContents::GetURL() because that uses the active entry,
  79   // whereas we want the visible entry.
  80   const content::NavigationEntry* entry =
  81       contents->GetController().GetVisibleEntry();
  82   if (entry && entry->GetVirtualURL() == GURL(chrome::kChromeUINewTabURL))
  83     return true;
  84
  85   return chrome::IsInstantNTP(contents);
  86 }
  87
  88 bool IsSearchResults(const content::WebContents* contents) {
  89   return !chrome::GetSearchTerms(contents).empty();
  90 }
  91
  92 bool IsLocal(const content::WebContents* contents) {
  93   if (!contents)
  94     return false;
  95   const content::NavigationEntry* entry =
  96       contents->GetController().GetVisibleEntry();
  97   return entry && entry->GetURL() == GURL(chrome::kChromeSearchLocalNtpUrl);
  98 }
  99
 100 // Returns true if |contents| are rendered inside an Instant process.
 101 bool InInstantProcess(Profile* profile,
 102                       const content::WebContents* contents) {
 103   if (!profile || !contents)
 104     return false;
 105
 106   InstantService* instant_service =
 107       InstantServiceFactory::GetForProfile(profile);
 108   return instant_service &&
 109       instant_service->IsInstantProcess(
 110           contents->GetRenderProcessHost()->GetID());
 111 }
 112
 113 // Updates the location bar to reflect |contents| Instant support state.
 114 void UpdateLocationBar(content::WebContents* contents) {
 115 // iOS and Android don't use the Instant framework.
 116 #if !defined(OS_IOS) && !defined(OS_ANDROID)
 117   if (!contents)
 118     return;
 119
 120   Browser* browser = chrome::FindBrowserWithWebContents(contents);
 121   if (!browser)
 122     return;
 123   browser->OnWebContentsInstantSupportDisabled(contents);
 124 #endif
 125 }
 126
 127 // Called when an NTP finishes loading. If the load start time was noted,
 128 // calculates and logs the total load time.
 129 void RecordNewTabLoadTime(content::WebContents* contents) {
 130   CoreTabHelper* core_tab_helper = CoreTabHelper::FromWebContents(contents);
 131   if (core_tab_helper->new_tab_start_time().is_null())
 132     return;
 133
 134   base::TimeDelta duration =
 135       base::TimeTicks::Now() - core_tab_helper->new_tab_start_time();
 136   UMA_HISTOGRAM_TIMES("Tab.NewTabOnload", duration);
 137   core_tab_helper->set_new_tab_start_time(base::TimeTicks());
 138 }
 139
 140 }  // namespace
 141
 142 SearchTabHelper::SearchTabHelper(content::WebContents* web_contents)
 143     : WebContentsObserver(web_contents),
 144       is_search_enabled_(chrome::IsInstantExtendedAPIEnabled()),
 145       user_input_in_progress_(false),
 146       web_contents_(web_contents),
 147       ipc_router_(web_contents, this,
 148                   make_scoped_ptr(new SearchIPCRouterPolicyImpl(web_contents))
 149                       .PassAs<SearchIPCRouter::Policy>()),
 150       instant_service_(NULL) {
 151   if (!is_search_enabled_)
 152     return;
 153
 154   instant_service_ =
 155       InstantServiceFactory::GetForProfile(
 156           Profile::FromBrowserContext(web_contents_->GetBrowserContext()));
 157   if (instant_service_)
 158     instant_service_->AddObserver(this);
 159 }
 160
 161 SearchTabHelper::~SearchTabHelper() {
 162   if (instant_service_)
 163     instant_service_->RemoveObserver(this);
 164 }
 165
 166 void SearchTabHelper::InitForPreloadedNTP() {
 167   UpdateMode(true, true);
 168 }
 169
 170 void SearchTabHelper::OmniboxEditModelChanged(bool user_input_in_progress,
 171                                               bool cancelling) {
 172   if (!is_search_enabled_)
 173     return;
 174
 175   user_input_in_progress_ = user_input_in_progress;
 176   if (!user_input_in_progress && !cancelling)
 177     return;
 178
 179   UpdateMode(false, false);
 180 }
 181
 182 void SearchTabHelper::NavigationEntryUpdated() {
 183   if (!is_search_enabled_)
 184     return;
 185
 186   UpdateMode(false, false);
 187 }
 188
 189 void SearchTabHelper::InstantSupportChanged(bool instant_support) {
 190   if (!is_search_enabled_)
 191     return;
 192
 193   InstantSupportState new_state = instant_support ? INSTANT_SUPPORT_YES :
 194       INSTANT_SUPPORT_NO;
 195
 196   model_.SetInstantSupportState(new_state);
 197
 198   content::NavigationEntry* entry =
 199       web_contents_->GetController().GetVisibleEntry();
 200   if (entry) {
 201     chrome::SetInstantSupportStateInNavigationEntry(new_state, entry);
 202     if (!instant_support)
 203       UpdateLocationBar(web_contents_);
 204   }
 205 }
 206
 207 bool SearchTabHelper::SupportsInstant() const {
 208   return model_.instant_support() == INSTANT_SUPPORT_YES;
 209 }
 210
 211 void SearchTabHelper::SetSuggestionToPrefetch(
 212     const InstantSuggestion& suggestion) {
 213   ipc_router_.SetSuggestionToPrefetch(suggestion);
 214 }
 215
 216 void SearchTabHelper::Submit(const base::string16& text) {
 217   ipc_router_.Submit(text);
 218 }
 219
 220 void SearchTabHelper::OnTabActivated() {
 221   ipc_router_.OnTabActivated();
 222 }
 223
 224 void SearchTabHelper::OnTabDeactivated() {
 225   ipc_router_.OnTabDeactivated();
 226 }
 227
 228 void SearchTabHelper::ToggleVoiceSearch() {
 229   ipc_router_.ToggleVoiceSearch();
 230 }
 231
 232 bool SearchTabHelper::IsSearchResultsPage() {
 233   return model_.mode().is_origin_search();
 234 }
 235
 236 void SearchTabHelper::RenderViewCreated(
 237     content::RenderViewHost* render_view_host) {
 238   ipc_router_.SetPromoInformation(IsAppLauncherEnabled());
 239 }
 240
 241 void SearchTabHelper::DidStartNavigationToPendingEntry(
 242     const GURL& url,
 243     content::NavigationController::ReloadType /* reload_type */) {
 244   if (chrome::IsNTPURL(url, profile())) {
 245     // Set the title on any pending entry corresponding to the NTP. This
 246     // prevents any flickering of the tab title.
 247     content::NavigationEntry* entry =
 248         web_contents_->GetController().GetPendingEntry();
 249     if (entry)
 250       entry->SetTitle(l10n_util::GetStringUTF16(IDS_NEW_TAB_TITLE));
 251   }
 252 }
 253
 254 void SearchTabHelper::DidNavigateMainFrame(
 255     const content::LoadCommittedDetails& details,
 256     const content::FrameNavigateParams& params) {
 257   if (IsCacheableNTP(web_contents_)) {
 258     if (details.http_status_code == 204 || details.http_status_code >= 400) {
 259       RedirectToLocalNTP();
 260       RecordCacheableNTPLoadHistogram(false);
 261       return;
 262     }
 263     RecordCacheableNTPLoadHistogram(true);
 264   }
 265
 266   // Always set the title on the new tab page to be the one from our UI
 267   // resources. Normally, we set the title when we begin a NTP load, but it can
 268   // get reset in several places (like when you press Reload). This check
 269   // ensures that the title is properly set to the string defined by the Chrome
 270   // UI language (rather than the server language) in all cases.
 271   //
 272   // We only override the title when it's nonempty to allow the page to set the
 273   // title if it really wants. An empty title means to use the default. There's
 274   // also a race condition between this code and the page's SetTitle call which
 275   // this rule avoids.
 276   content::NavigationEntry* entry =
 277       web_contents_->GetController().GetLastCommittedEntry();
 278   if (entry && entry->GetTitle().empty() &&
 279       (entry->GetVirtualURL() == GURL(chrome::kChromeUINewTabURL) ||
 280        chrome::NavEntryIsInstantNTP(web_contents_, entry))) {
 281     entry->SetTitle(l10n_util::GetStringUTF16(IDS_NEW_TAB_TITLE));
 282   }
 283 }
 284
 285 void SearchTabHelper::DidFailProvisionalLoad(
 286     int64 /* frame_id */,
 287     const base::string16& /* frame_unique_name */,
 288     bool is_main_frame,
 289     const GURL& validated_url,
 290     int error_code,
 291     const base::string16& /* error_description */,
 292     content::RenderViewHost* /* render_view_host */) {
 293   // If error_code is ERR_ABORTED means that the user has canceled this
 294   // navigation so it shouldn't be redirected.
 295   if (is_main_frame &&
 296       error_code != net::ERR_ABORTED &&
 297       validated_url != GURL(chrome::kChromeSearchLocalNtpUrl) &&
 298       chrome::IsNTPURL(validated_url, profile())) {
 299     RedirectToLocalNTP();
 300     RecordCacheableNTPLoadHistogram(false);
 301   }
 302 }
 303
 304 void SearchTabHelper::DidFinishLoad(
 305     int64 /* frame_id */,
 306     const GURL&  /* validated_url */,
 307     bool is_main_frame,
 308     content::RenderViewHost* /* render_view_host */) {
 309   if (is_main_frame) {
 310     if (chrome::IsInstantNTP(web_contents_))
 311       RecordNewTabLoadTime(web_contents_);
 312
 313     DetermineIfPageSupportsInstant();
 314   }
 315 }
 316
 317 void SearchTabHelper::NavigationEntryCommitted(
 318     const content::LoadCommittedDetails& load_details) {
 319   if (!is_search_enabled_)
 320     return;
 321
 322   if (!load_details.is_main_frame)
 323     return;
 324
 325   // TODO(kmadhusu): Set the page initial states (such as omnibox margin, etc)
 326   // from here. Please refer to crbug.com/247517 for more details.
 327   if (chrome::ShouldAssignURLToInstantRenderer(web_contents_->GetURL(),
 328                                                profile())) {
 329     ipc_router_.SetDisplayInstantResults();
 330   }
 331
 332   UpdateMode(true, false);
 333
 334   content::NavigationEntry* entry =
 335       web_contents_->GetController().GetVisibleEntry();
 336   DCHECK(entry);
 337
 338   // Already determined the instant support state for this page, do not reset
 339   // the instant support state.
 340   //
 341   // When we get a navigation entry committed event, there seem to be two ways
 342   // to tell whether the navigation was "in-page". Ideally, when
 343   // LoadCommittedDetails::is_in_page is true, we should have
 344   // LoadCommittedDetails::type to be NAVIGATION_TYPE_IN_PAGE. Unfortunately,
 345   // they are different in some cases. To workaround this bug, we are checking
 346   // (is_in_page || type == NAVIGATION_TYPE_IN_PAGE). Please refer to
 347   // crbug.com/251330 for more details.
 348   if (load_details.is_in_page ||
 349       load_details.type == content::NAVIGATION_TYPE_IN_PAGE) {
 350     // When an "in-page" navigation happens, we will not receive a
 351     // DidFinishLoad() event. Therefore, we will not determine the Instant
 352     // support for the navigated page. So, copy over the Instant support from
 353     // the previous entry. If the page does not support Instant, update the
 354     // location bar from here to turn off search terms replacement.
 355     chrome::SetInstantSupportStateInNavigationEntry(model_.instant_support(),
 356                                                     entry);
 357     if (model_.instant_support() == INSTANT_SUPPORT_NO)
 358       UpdateLocationBar(web_contents_);
 359     return;
 360   }
 361
 362   model_.SetInstantSupportState(INSTANT_SUPPORT_UNKNOWN);
 363   model_.SetVoiceSearchSupported(false);
 364   chrome::SetInstantSupportStateInNavigationEntry(model_.instant_support(),
 365                                                   entry);
 366 }
 367
 368 void SearchTabHelper::OnInstantSupportDetermined(bool supports_instant) {
 369   InstantSupportChanged(supports_instant);
 370 }
 371
 372 void SearchTabHelper::OnSetVoiceSearchSupport(bool supports_voice_search) {
 373   model_.SetVoiceSearchSupported(supports_voice_search);
 374 }
 375
 376 void SearchTabHelper::ThemeInfoChanged(const ThemeBackgroundInfo& theme_info) {
 377   ipc_router_.SendThemeBackgroundInfo(theme_info);
 378 }
 379
 380 void SearchTabHelper::MostVisitedItemsChanged(
 381     const std::vector<InstantMostVisitedItem>& items) {
 382   std::vector<InstantMostVisitedItem> items_copy(items);
 383   MaybeRemoveMostVisitedItems(&items_copy);
 384   ipc_router_.SendMostVisitedItems(items_copy);
 385 }
 386
 387 void SearchTabHelper::MaybeRemoveMostVisitedItems(
 388     std::vector<InstantMostVisitedItem>* items) {
 389 // The code below uses APIs not available on Android and the experiment should
 390 // not run there.
 391 #if !defined(OS_ANDROID)
 392   if (!history::MostVisitedTilesExperiment::IsDontShowOpenURLsEnabled())
 393     return;
 394
 395   Profile* profile =
 396       Profile::FromBrowserContext(web_contents_->GetBrowserContext());
 397   if (!profile)
 398     return;
 399
 400   Browser* browser = chrome::FindBrowserWithProfile(profile,
 401                                                     chrome::GetActiveDesktop());
 402   if (!browser)
 403     return;
 404
 405   TabStripModel* tab_strip_model = browser->tab_strip_model();
 406   history::TopSites* top_sites = profile->GetTopSites();
 407   if (!tab_strip_model || !top_sites) {
 408     NOTREACHED();
 409     return;
 410   }
 411
 412   std::set<std::string> open_urls;
 413   chrome::GetOpenUrls(*tab_strip_model, *top_sites, &open_urls);
 414   history::MostVisitedTilesExperiment::RemoveItemsMatchingOpenTabs(
 415       open_urls, items);
 416 #endif
 417 }
 418
 419 void SearchTabHelper::FocusOmnibox(OmniboxFocusState state) {
 420 // iOS and Android don't use the Instant framework.
 421 #if !defined(OS_IOS) && !defined(OS_ANDROID)
 422   Browser* browser = chrome::FindBrowserWithWebContents(web_contents());
 423   if (!browser)
 424     return;
 425
 426   OmniboxView* omnibox = browser->window()->GetLocationBar()->GetOmniboxView();
 427   // Do not add a default case in the switch block for the following reasons:
 428   // (1) Explicitly handle the new states. If new states are added in the
 429   // OmniboxFocusState, the compiler will warn the developer to handle the new
 430   // states.
 431   // (2) An attacker may control the renderer and sends the browser process a
 432   // malformed IPC. This function responds to the invalid |state| values by
 433   // doing nothing instead of crashing the browser process (intentional no-op).
 434   switch (state) {
 435     case OMNIBOX_FOCUS_VISIBLE:
 436       omnibox->SetFocus();
 437       omnibox->model()->SetCaretVisibility(true);
 438       break;
 439     case OMNIBOX_FOCUS_INVISIBLE:
 440       omnibox->SetFocus();
 441       omnibox->model()->SetCaretVisibility(false);
 442       // If the user clicked on the fakebox, any text already in the omnibox
 443       // should get cleared when they start typing. Selecting all the existing
 444       // text is a convenient way to accomplish this. It also gives a slight
 445       // visual cue to users who really understand selection state about what
 446       // will happen if they start typing.
 447       omnibox->SelectAll(false);
 448       break;
 449     case OMNIBOX_FOCUS_NONE:
 450       // Remove focus only if the popup is closed. This will prevent someone
 451       // from changing the omnibox value and closing the popup without user
 452       // interaction.
 453       if (!omnibox->model()->popup_model()->IsOpen())
 454         web_contents()->GetView()->Focus();
 455       break;
 456   }
 457 #endif
 458 }
 459
 460 void SearchTabHelper::NavigateToURL(const GURL& url,
 461                                     WindowOpenDisposition disposition,
 462                                     bool is_most_visited_item_url) {
 463 // iOS and Android don't use the Instant framework.
 464 #if !defined(OS_IOS) && !defined(OS_ANDROID)
 465   // TODO(kmadhusu): Remove chrome::FindBrowser...() function call from here.
 466   // Create a SearchTabHelperDelegate interface and have the Browser object
 467   // implement that interface to provide the necessary functionality.
 468   Browser* browser = chrome::FindBrowserWithWebContents(web_contents_);
 469   Profile* profile =
 470       Profile::FromBrowserContext(web_contents_->GetBrowserContext());
 471   if (!browser || !profile)
 472     return;
 473
 474   if (is_most_visited_item_url) {
 475     content::RecordAction(
 476         base::UserMetricsAction("InstantExtended.MostVisitedClicked"));
 477   }
 478
 479   chrome::NavigateParams params(browser, url,
 480                                 content::PAGE_TRANSITION_AUTO_BOOKMARK);
 481   params.referrer = content::Referrer();
 482   params.source_contents = web_contents_;
 483   params.disposition = disposition;
 484   params.is_renderer_initiated = false;
 485   params.initiating_profile = profile;
 486   chrome::Navigate(&params);
 487 #endif
 488 }
 489
 490 void SearchTabHelper::OnDeleteMostVisitedItem(const GURL& url) {
 491   DCHECK(!url.is_empty());
 492   if (instant_service_)
 493     instant_service_->DeleteMostVisitedItem(url);
 494 }
 495
 496 void SearchTabHelper::OnUndoMostVisitedDeletion(const GURL& url) {
 497   DCHECK(!url.is_empty());
 498   if (instant_service_)
 499     instant_service_->UndoMostVisitedDeletion(url);
 500 }
 501
 502 void SearchTabHelper::OnUndoAllMostVisitedDeletions() {
 503   if (instant_service_)
 504     instant_service_->UndoAllMostVisitedDeletions();
 505 }
 506
 507 void SearchTabHelper::OnLogEvent(NTPLoggingEventType event) {
 508   NTPUserDataLogger::GetOrCreateFromWebContents(
 509       web_contents())->LogEvent(event);
 510 }
 511
 512 void SearchTabHelper::OnLogImpression(int position,
 513                                       const base::string16& provider) {
 514   NTPUserDataLogger::GetOrCreateFromWebContents(
 515       web_contents())->LogImpression(position, provider);
 516 }
 517
 518 void SearchTabHelper::PasteIntoOmnibox(const base::string16& text) {
 519 // iOS and Android don't use the Instant framework.
 520 #if !defined(OS_IOS) && !defined(OS_ANDROID)
 521   Browser* browser = chrome::FindBrowserWithWebContents(web_contents());
 522   if (!browser)
 523     return;
 524
 525   OmniboxView* omnibox = browser->window()->GetLocationBar()->GetOmniboxView();
 526   // The first case is for right click to paste, where the text is retrieved
 527   // from the clipboard already sanitized. The second case is needed to handle
 528   // drag-and-drop value and it has to be sanitazed before setting it into the
 529   // omnibox.
 530   base::string16 text_to_paste = text.empty() ? omnibox->GetClipboardText() :
 531       omnibox->SanitizeTextForPaste(text);
 532
 533   if (text_to_paste.empty())
 534     return;
 535
 536   if (!omnibox->model()->has_focus())
 537     omnibox->SetFocus();
 538
 539   omnibox->OnBeforePossibleChange();
 540   omnibox->model()->OnPaste();
 541   omnibox->SetUserText(text_to_paste);
 542   omnibox->OnAfterPossibleChange();
 543 #endif
 544 }
 545
 546 void SearchTabHelper::OnChromeIdentityCheck(const base::string16& identity) {
 547   SigninManagerBase* manager = SigninManagerFactory::GetForProfile(profile());
 548   if (manager) {
 549     const base::string16 username =
 550         base::UTF8ToUTF16(manager->GetAuthenticatedUsername());
 551     ipc_router_.SendChromeIdentityCheckResult(identity,
 552                                               identity == username);
 553   }
 554 }
 555
 556 void SearchTabHelper::UpdateMode(bool update_origin, bool is_preloaded_ntp) {
 557   SearchMode::Type type = SearchMode::MODE_DEFAULT;
 558   SearchMode::Origin origin = SearchMode::ORIGIN_DEFAULT;
 559   if (IsNTP(web_contents_) || is_preloaded_ntp) {
 560     type = SearchMode::MODE_NTP;
 561     origin = SearchMode::ORIGIN_NTP;
 562   } else if (IsSearchResults(web_contents_)) {
 563     type = SearchMode::MODE_SEARCH_RESULTS;
 564     origin = SearchMode::ORIGIN_SEARCH;
 565   }
 566   if (!update_origin)
 567     origin = model_.mode().origin;
 568   if (user_input_in_progress_)
 569     type = SearchMode::MODE_SEARCH_SUGGESTIONS;
 570   model_.SetMode(SearchMode(type, origin));
 571 }
 572
 573 void SearchTabHelper::DetermineIfPageSupportsInstant() {
 574   if (!InInstantProcess(profile(), web_contents_)) {
 575     // The page is not in the Instant process. This page does not support
 576     // instant. If we send an IPC message to a page that is not in the Instant
 577     // process, it will never receive it and will never respond. Therefore,
 578     // return immediately.
 579     InstantSupportChanged(false);
 580   } else if (IsLocal(web_contents_)) {
 581     // Local pages always support Instant.
 582     InstantSupportChanged(true);
 583   } else {
 584     ipc_router_.DetermineIfPageSupportsInstant();
 585   }
 586 }
 587
 588 Profile* SearchTabHelper::profile() const {
 589   return Profile::FromBrowserContext(web_contents_->GetBrowserContext());
 590 }
 591
 592 void SearchTabHelper::RedirectToLocalNTP() {
 593   // Extra parentheses to declare a variable.
 594   content::NavigationController::LoadURLParams load_params(
 595       (GURL(chrome::kChromeSearchLocalNtpUrl)));
 596   load_params.referrer = content::Referrer();
 597   load_params.transition_type = content::PAGE_TRANSITION_SERVER_REDIRECT;
 598   // Don't push a history entry.
 599   load_params.should_replace_current_entry = true;
 600   web_contents_->GetController().LoadURLWithParams(load_params);
 601 }