Instant: Use only one hidden WebContents per profile.

chrome/browser/instant/instant_controller.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/instant/instant_controller.h"
 
-#include "base/command_line.h"
-#include "base/metrics/histogram.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
-#include "base/utf_string_conversions.h"
-#include "chrome/browser/autocomplete/autocomplete_provider.h"
-#include "chrome/browser/history/history_service.h"
-#include "chrome/browser/history/history_service_factory.h"
-#include "chrome/browser/history/history_tab_helper.h"
-#include "chrome/browser/history/top_sites.h"
-#include "chrome/browser/instant/instant_ntp.h"
-#include "chrome/browser/instant/instant_overlay.h"
-#include "chrome/browser/instant/instant_tab.h"
-#include "chrome/browser/platform_util.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_instant_controller.h"
+#include "chrome/browser/instant/instant_controller_extended_impl.h"
+#include "chrome/browser/instant/instant_controller_impl.h"
 #include "chrome/browser/ui/search/search.h"
-#include "chrome/browser/ui/search/search_tab_helper.h"
-#include "chrome/common/chrome_notification_types.h"
-#include "chrome/common/chrome_switches.h"
-#include "chrome/common/url_constants.h"
-#include "content/public/browser/navigation_entry.h"
-#include "content/public/browser/notification_service.h"
-#include "content/public/browser/render_widget_host_view.h"
-#include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents_view.h"
-#include "net/base/escape.h"
-#include "third_party/icu/public/common/unicode/normalizer2.h"
 
-#if defined(TOOLKIT_VIEWS)
-#include "ui/views/widget/widget.h"
-#endif
-
-namespace {
-
-// An artificial delay (in milliseconds) we introduce before telling the Instant
-// page about the new omnibox bounds, in cases where the bounds shrink. This is
-// to avoid the page jumping up/down very fast in response to bounds changes.
-const int kUpdateBoundsDelayMS = 1000;
-
-// The maximum number of times we'll load a non-Instant-supporting search engine
-// before we give up and blacklist it for the rest of the browsing session.
-const int kMaxInstantSupportFailures = 10;
-
-// For reporting events of interest.
-enum InstantControllerEvent {
-  INSTANT_CONTROLLER_EVENT_URL_ADDED_TO_BLACKLIST = 0,
-  INSTANT_CONTROLLER_EVENT_URL_REMOVED_FROM_BLACKLIST = 1,
-  INSTANT_CONTROLLER_EVENT_URL_BLOCKED_BY_BLACKLIST = 2,
-  INSTANT_CONTROLLER_EVENT_MAX = 3,
-};
-
-void RecordEventHistogram(InstantControllerEvent event) {
-  UMA_HISTOGRAM_ENUMERATION("Instant.InstantControllerEvent",
-                            event,
-                            INSTANT_CONTROLLER_EVENT_MAX);
+// static
+scoped_ptr<InstantController> InstantController::GetInstance(
+    chrome::BrowserInstantController* browser,
+    Profile* profile) {
+  InstantController* instance;
+  if (chrome::search::IsInstantExtendedAPIEnabled(profile))
+    instance = new InstantControllerExtendedImpl(browser, profile);

[samarth, 2013/03/01 17:59:53]

Just return here (and below) instead of saving to a local variable first.

[sreeram, 2013/03/07 18:18:46]

Done.

+  else
+    instance = new InstantControllerImpl(browser, profile);
+  return scoped_ptr<InstantController>(instance);
 }
 
-void AddSessionStorageHistogram(bool extended_enabled,
-                                const content::WebContents* tab1,
-                                const content::WebContents* tab2) {
-  base::HistogramBase* histogram = base::BooleanHistogram::FactoryGet(
-      std::string("Instant.SessionStorageNamespace") +
-          (extended_enabled ? "_Extended" : "_Instant"),
-      base::HistogramBase::kUmaTargetedHistogramFlag);
-  const content::SessionStorageNamespaceMap& session_storage_map1 =
-      tab1->GetController().GetSessionStorageNamespaceMap();
-  const content::SessionStorageNamespaceMap& session_storage_map2 =
-      tab2->GetController().GetSessionStorageNamespaceMap();
-  bool is_session_storage_the_same =
-      session_storage_map1.size() == session_storage_map2.size();
-  if (is_session_storage_the_same) {
-    // The size is the same, so let's check that all entries match.
-    for (content::SessionStorageNamespaceMap::const_iterator
-             it1 = session_storage_map1.begin(),
-             it2 = session_storage_map2.begin();
-         it1 != session_storage_map1.end() && it2 != session_storage_map2.end();
-         ++it1, ++it2) {
-      if (it1->first != it2->first || it1->second != it2->second) {
-        is_session_storage_the_same = false;
-        break;
-      }
-    }
-  }
-  histogram->AddBoolean(is_session_storage_the_same);
-}
-
-string16 Normalize(const string16& str) {
-  UErrorCode status = U_ZERO_ERROR;
-  const icu::Normalizer2* normalizer =
-      icu::Normalizer2::getInstance(NULL, "nfkc_cf", UNORM2_COMPOSE, status);
-  if (normalizer == NULL || U_FAILURE(status))
-    return str;
-  icu::UnicodeString norm_str(normalizer->normalize(
-      icu::UnicodeString(FALSE, str.c_str(), str.size()), status));
-  if (U_FAILURE(status))
-    return str;
-  return string16(norm_str.getBuffer(), norm_str.length());
-}
-
-bool NormalizeAndStripPrefix(string16* text, const string16& prefix) {
-  string16 norm_prefix = Normalize(prefix);
-  string16 norm_text = Normalize(*text);
-  if (norm_prefix.size() <= norm_text.size() &&
-      norm_text.compare(0, norm_prefix.size(), norm_prefix) == 0) {
-    *text = norm_text.erase(0, norm_prefix.size());
-    return true;
-  }
-  return false;
-}
-
-// For TOOLKIT_VIEWS, the top level widget is always focused. If the focus
-// change originated in views determine the child Widget from the view that is
-// being focused.
-gfx::NativeView GetViewGainingFocus(gfx::NativeView view_gaining_focus) {
-#if defined(TOOLKIT_VIEWS)
-  views::Widget* widget = view_gaining_focus ?
-      views::Widget::GetWidgetForNativeView(view_gaining_focus) : NULL;
-  if (widget) {
-    views::FocusManager* focus_manager = widget->GetFocusManager();
-    if (focus_manager && focus_manager->is_changing_focus() &&
-        focus_manager->GetFocusedView() &&
-        focus_manager->GetFocusedView()->GetWidget())
-      return focus_manager->GetFocusedView()->GetWidget()->GetNativeView();
-  }
-#endif
-  return view_gaining_focus;
-}
-
-// Returns true if |view| is the top-level contents view or a child view in the
-// view hierarchy of |contents|.
-bool IsViewInContents(gfx::NativeView view, content::WebContents* contents) {
-  content::RenderWidgetHostView* rwhv = contents->GetRenderWidgetHostView();
-  if (!view || !rwhv)
-    return false;
-
-  gfx::NativeView tab_view = contents->GetView()->GetNativeView();
-  if (view == rwhv->GetNativeView() || view == tab_view)
-    return true;
-
-  // Walk up the view hierarchy to determine if the view is a subview of the
-  // WebContents view (such as a windowed plugin or http auth dialog).
-  while (view) {
-    view = platform_util::GetParent(view);
-    if (view == tab_view)
-      return true;
-  }
-
-  return false;
-}
-
-bool IsFullHeight(const InstantModel& model) {
-  return model.height() == 100 && model.height_units() == INSTANT_SIZE_PERCENT;
-}
-
-bool IsContentsFrom(const InstantPage* page,
-                    const content::WebContents* contents) {
-  return page && (page->contents() == contents);
-}
-
-// Adds a transient NavigationEntry to the supplied |contents|'s
-// NavigationController if the page's URL has not already been updated with the
-// supplied |search_terms|. Sets the |search_terms| on the transient entry for
-// search terms extraction to work correctly.
-void EnsureSearchTermsAreSet(content::WebContents* contents,
-                             const string16& search_terms) {
-  content::NavigationController& controller = contents->GetController();
-
-  // If search terms are already correct or there is already a transient entry
-  // (there shouldn't be), bail out early.
-  if (chrome::search::GetSearchTerms(contents) == search_terms ||
-      controller.GetTransientEntry())
-    return;
-
-  content::NavigationEntry* transient = content::NavigationEntry::Create(
-      *controller.GetActiveEntry());
-  transient->SetExtraData(chrome::search::kInstantExtendedSearchTermsKey,
-                          search_terms);
-  controller.SetTransientEntry(transient);
-
-  chrome::search::SearchTabHelper::FromWebContents(contents)->
-      NavigationEntryUpdated();
-}
-
-}  // namespace
-
-InstantController::InstantController(chrome::BrowserInstantController* browser,
-                                     bool extended_enabled)
-    : browser_(browser),
-      extended_enabled_(extended_enabled),
-      instant_enabled_(false),
-      use_local_preview_only_(true),
-      model_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
-      last_omnibox_text_has_inline_autocompletion_(false),
-      last_verbatim_(false),
-      last_transition_type_(content::PAGE_TRANSITION_LINK),
-      last_match_was_search_(false),
-      omnibox_focus_state_(OMNIBOX_FOCUS_NONE),
-      allow_preview_to_show_search_suggestions_(false),
-      ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {
+InstantController::InstantController() {
 }
 
 InstantController::~InstantController() {
 }
-
-bool InstantController::Update(const AutocompleteMatch& match,
-                               const string16& user_text,
-                               const string16& full_text,
-                               size_t selection_start,
-                               size_t selection_end,
-                               bool verbatim,
-                               bool user_input_in_progress,
-                               bool omnibox_popup_is_open,
-                               bool escape_pressed,
-                               bool is_keyword_search) {
-  if (!extended_enabled_ && !instant_enabled_)
-    return false;
-
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "Update: %s user_text='%s' full_text='%s' selection_start=%d "
-      "selection_end=%d verbatim=%d typing=%d popup=%d escape_pressed=%d "
-      "is_keyword_search=%d",
-      AutocompleteMatch::TypeToString(match.type).c_str(),
-      UTF16ToUTF8(user_text).c_str(), UTF16ToUTF8(full_text).c_str(),
-      static_cast<int>(selection_start), static_cast<int>(selection_end),
-      verbatim, user_input_in_progress, omnibox_popup_is_open, escape_pressed,
-      is_keyword_search));
-
-  // TODO(dhollowa): Complete keyword match UI.  For now just hide suggestions.
-  // http://crbug.com/153932.  Note, this early escape is happens prior to the
-  // DCHECKs below because |user_text| and |full_text| have different semantics
-  // when keyword search is in effect.
-  if (is_keyword_search) {
-    if (instant_tab_)
-      instant_tab_->Update(string16(), 0, 0, true);
-    else
-      HideOverlay();
-    last_match_was_search_ = false;
-    return false;
-  }
-
-  // If the popup is open, the user has to be typing.
-  DCHECK(!omnibox_popup_is_open || user_input_in_progress);
-
-  // If the popup is closed, there should be no inline autocompletion.
-  DCHECK(omnibox_popup_is_open || user_text.empty() || user_text == full_text)
-      << user_text << "|" << full_text;
-
-  // If there's no text in the omnibox, the user can't have typed any.
-  DCHECK(!full_text.empty() || user_text.empty()) << user_text;
-
-  // If the user isn't typing, and the popup is closed, there can't be any
-  // user-typed text.
-  DCHECK(user_input_in_progress || omnibox_popup_is_open || user_text.empty())
-      << user_text;
-
-  // The preview is being clicked and will commit soon. Don't change anything.
-  // TODO(sreeram): Add a browser test for this.
-  if (overlay_ && overlay_->is_pointer_down_from_activate())
-    return false;
-
-  // In non-extended mode, SearchModeChanged() is never called, so fake it. The
-  // mode is set to "disallow suggestions" here, so that if one of the early
-  // "return false" conditions is hit, suggestions will be disallowed. If the
-  // query is sent to the overlay, the mode is set to "allow" further below.
-  if (!extended_enabled_)
-    search_mode_.mode = chrome::search::Mode::MODE_DEFAULT;
-
-  last_match_was_search_ = AutocompleteMatch::IsSearchType(match.type) &&
-                           !user_text.empty();
-
-  // In non extended mode, Instant is disabled for URLs and keyword mode.
-  if (!extended_enabled_ &&
-      (!last_match_was_search_ ||
-       match.type == AutocompleteMatch::SEARCH_OTHER_ENGINE)) {
-    HideOverlay();
-    return false;
-  }
-
-  // If we have an |instant_tab_| use it, else ensure we have a overlay that is
-  // current or is using local preview.
-  if (!instant_tab_ && !(overlay_ && overlay_->IsUsingLocalPreview()) &&
-      !EnsureOverlayIsCurrent(false)) {
-    HideOverlay();
-    return false;
-  }
-
-  if (extended_enabled_) {
-    if (!omnibox_popup_is_open) {
-      if (!user_input_in_progress) {
-        // If the user isn't typing and the omnibox popup is closed, it means a
-        // regular navigation, tab-switch or the user hitting Escape.
-        if (instant_tab_) {
-          // The user is on a search results page. It may be showing results for
-          // a partial query the user typed before they hit Escape. Send the
-          // omnibox text to the page to restore the original results.
-          //
-          // In a tab switch, |instant_tab_| won't have updated yet, so it may
-          // be pointing to the previous tab (which was a search results page).
-          // Ensure we don't send the omnibox text to a random webpage (the new
-          // tab), by comparing the old and new WebContents.
-          if (escape_pressed &&
-              instant_tab_->contents() == browser_->GetActiveWebContents()) {
-            instant_tab_->Submit(full_text);
-          }
-        } else if (!full_text.empty()) {
-          // If |full_text| is empty, the user is on the NTP. The preview may
-          // be showing custom NTP content; hide only if that's not the case.
-          HideOverlay();
-        }
-      } else if (full_text.empty()) {
-        // The user is typing, and backspaced away all omnibox text. Clear
-        // |last_omnibox_text_| so that we don't attempt to set suggestions.
-        last_omnibox_text_.clear();
-        last_suggestion_ = InstantSuggestion();
-        if (instant_tab_) {
-          // On a search results page, tell it to clear old results.
-          instant_tab_->Update(string16(), 0, 0, true);
-        } else if (search_mode_.is_origin_ntp()) {
-          // On the NTP, tell the preview to clear old results. Don't hide the
-          // preview so it can show a blank page or logo if it wants.
-          overlay_->Update(string16(), 0, 0, true);
-        } else {
-          HideOverlay();
-        }
-      } else {
-        // The user switched to a tab with partial text already in the omnibox.
-        HideOverlay();
-
-        // The new tab may or may not be a search results page; we don't know
-        // since SearchModeChanged() hasn't been called yet. If it later turns
-        // out to be, we should store |full_text| now, so that if the user hits
-        // Enter, we'll send the correct query to instant_tab_->Submit(). If the
-        // partial text is not a query (|last_match_was_search_| is false), we
-        // won't Submit(), so no need to worry about that.
-        last_omnibox_text_ = full_text;
-        last_suggestion_ = InstantSuggestion();
-      }
-      return false;
-    } else if (full_text.empty()) {
-      // The user typed a solitary "?". Same as the backspace case above.
-      last_omnibox_text_.clear();
-      last_suggestion_ = InstantSuggestion();
-      if (instant_tab_)
-        instant_tab_->Update(string16(), 0, 0, true);
-      else if (search_mode_.is_origin_ntp())
-        overlay_->Update(string16(), 0, 0, true);
-      else
-        HideOverlay();
-      return false;
-    }
-  } else if (!omnibox_popup_is_open || full_text.empty()) {
-    // In the non-extended case, hide the preview as long as the user isn't
-    // actively typing a non-empty query.
-    HideOverlay();
-    return false;
-  }
-
-  last_omnibox_text_has_inline_autocompletion_ = user_text != full_text;
-
-  // If the user continues typing the same query as the suggested text is
-  // showing, reuse the suggestion (but only for INSTANT_COMPLETE_NEVER).
-  bool reused_suggestion = false;
-  if (last_suggestion_.behavior == INSTANT_COMPLETE_NEVER &&
-      !last_omnibox_text_has_inline_autocompletion_) {
-    if (StartsWith(last_omnibox_text_, full_text, false)) {
-      // The user is backspacing away characters.
-      last_suggestion_.text.insert(0, last_omnibox_text_, full_text.size(),
-          last_omnibox_text_.size() - full_text.size());
-      reused_suggestion = true;
-    } else if (StartsWith(full_text, last_omnibox_text_, false)) {
-      // The user is typing forward. Normalize any added characters.
-      reused_suggestion = NormalizeAndStripPrefix(&last_suggestion_.text,
-          string16(full_text, last_omnibox_text_.size()));
-    }
-  }
-  if (!reused_suggestion)
-    last_suggestion_ = InstantSuggestion();
-
-  last_omnibox_text_ = full_text;
-
-  if (!extended_enabled_) {
-    // In non-extended mode, the query is verbatim if there's any selection
-    // (including inline autocompletion) or if the cursor is not at the end.
-    verbatim = verbatim || selection_start != selection_end ||
-                           selection_start != full_text.size();
-  }
-  last_verbatim_ = verbatim;
-
-  last_transition_type_ = match.transition;
-  url_for_history_ = match.destination_url;
-
-  // Allow search suggestions. In extended mode, SearchModeChanged() will set
-  // this, but it's not called in non-extended mode, so fake it.
-  if (!extended_enabled_)
-    search_mode_.mode = chrome::search::Mode::MODE_SEARCH_SUGGESTIONS;
-
-  if (instant_tab_) {
-    instant_tab_->Update(user_text, selection_start, selection_end, verbatim);
-  } else {
-    if (first_interaction_time_.is_null())
-      first_interaction_time_ = base::Time::Now();
-    allow_preview_to_show_search_suggestions_ = true;
-
-    // For extended mode, if the loader is not ready at this point, switch over
-    // to a backup loader.
-    if (extended_enabled_ && !overlay_->supports_instant() &&
-        !overlay_->IsUsingLocalPreview() && browser_->GetActiveWebContents()) {
-      CreateOverlay(chrome::search::kLocalOmniboxPopupURL,
-                    browser_->GetActiveWebContents());
-    }
-
-    overlay_->Update(extended_enabled_ ? user_text : full_text,
-                     selection_start, selection_end, verbatim);
-  }
-
-  content::NotificationService::current()->Notify(
-      chrome::NOTIFICATION_INSTANT_CONTROLLER_UPDATED,
-      content::Source<InstantController>(this),
-      content::NotificationService::NoDetails());
-
-  // We don't have new suggestions yet, but we can either reuse the existing
-  // suggestion or reset the existing "gray text".
-  browser_->SetInstantSuggestion(last_suggestion_);
-
-  return true;
-}
-
-scoped_ptr<content::WebContents> InstantController::ReleaseNTPContents() {
-  if (!extended_enabled_ || !ntp_)
-    return scoped_ptr<content::WebContents>(NULL);
-
-  LOG_INSTANT_DEBUG_EVENT(this, "ReleaseNTPContents");
-
-  scoped_ptr<content::WebContents> ntp_contents = ntp_->ReleaseContents();
-  ntp_.reset();
-  ResetNTP();
-  return ntp_contents.Pass();
-}
-
-// TODO(tonyg): This method only fires when the omnibox bounds change. It also
-// needs to fire when the preview bounds change (e.g.: open/close info bar).
-void InstantController::SetPopupBounds(const gfx::Rect& bounds) {
-  if (!extended_enabled_ && !instant_enabled_)
-    return;
-
-  if (popup_bounds_ == bounds)
-    return;
-
-  popup_bounds_ = bounds;
-  if (popup_bounds_.height() > last_popup_bounds_.height()) {
-    update_bounds_timer_.Stop();
-    SendPopupBoundsToPage();
-  } else if (!update_bounds_timer_.IsRunning()) {
-    update_bounds_timer_.Start(FROM_HERE,
-        base::TimeDelta::FromMilliseconds(kUpdateBoundsDelayMS), this,
-        &InstantController::SendPopupBoundsToPage);
-  }
-}
-
-void InstantController::SetOmniboxBounds(const gfx::Rect& bounds) {
-  if (!extended_enabled_ || omnibox_bounds_ == bounds)
-    return;
-
-  omnibox_bounds_ = bounds;
-  if (overlay_)
-    overlay_->SetOmniboxBounds(omnibox_bounds_);
-  if (ntp_)
-    ntp_->SetOmniboxBounds(omnibox_bounds_);
-  if (instant_tab_)
-    instant_tab_->SetOmniboxBounds(omnibox_bounds_);
-}
-
-void InstantController::HandleAutocompleteResults(
-    const std::vector<AutocompleteProvider*>& providers) {
-  if (!extended_enabled_)
-    return;
-
-  if (!instant_tab_ && !overlay_)
-    return;
-
-  DVLOG(1) << "AutocompleteResults:";
-  std::vector<InstantAutocompleteResult> results;
-  for (ACProviders::const_iterator provider = providers.begin();
-       provider != providers.end(); ++provider) {
-    for (ACMatches::const_iterator match = (*provider)->matches().begin();
-         match != (*provider)->matches().end(); ++match) {
-      InstantAutocompleteResult result;
-      result.provider = UTF8ToUTF16((*provider)->GetName());
-      result.type = UTF8ToUTF16(AutocompleteMatch::TypeToString(match->type));
-      result.description = match->description;
-      result.destination_url = UTF8ToUTF16(match->destination_url.spec());
-      result.transition = match->transition;
-      result.relevance = match->relevance;
-      DVLOG(1) << "    " << result.relevance << " " << result.type << " "
-               << result.provider << " " << result.destination_url << " '"
-               << result.description << "' " <<  result.transition;
-      results.push_back(result);
-    }
-  }
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "HandleAutocompleteResults: total_results=%d",
-      static_cast<int>(results.size())));
-
-  if (instant_tab_)
-    instant_tab_->SendAutocompleteResults(results);
-  else
-    overlay_->SendAutocompleteResults(results);
-}
-
-bool InstantController::OnUpOrDownKeyPressed(int count) {
-  if (!extended_enabled_)
-    return false;
-
-  if (!instant_tab_ && !overlay_)
-    return false;
-
-  if (instant_tab_)
-    instant_tab_->UpOrDownKeyPressed(count);
-  else
-    overlay_->UpOrDownKeyPressed(count);
-
-  return true;
-}
-
-void InstantController::OnCancel(const AutocompleteMatch& match,
-                                 const string16& full_text) {
-  if (!extended_enabled_)
-    return;
-
-  if (!instant_tab_ && !overlay_)
-    return;
-
-  // We manually reset the state here since the JS is not expected to do it.
-  // TODO(sreeram): Handle the case where user_text is now a URL
-  last_match_was_search_ = AutocompleteMatch::IsSearchType(match.type) &&
-                           !full_text.empty();
-  last_omnibox_text_ = full_text;
-  last_suggestion_ = InstantSuggestion();
-
-  if (instant_tab_)
-    instant_tab_->CancelSelection(full_text);
-  else
-    overlay_->CancelSelection(full_text);
-}
-
-content::WebContents* InstantController::GetPreviewContents() const {
-  return overlay_ ? overlay_->contents() : NULL;
-}
-
-bool InstantController::IsPreviewingSearchResults() const {
-  return model_.mode().is_search_suggestions() && IsFullHeight(model_) &&
-         (last_match_was_search_ ||
-          last_suggestion_.behavior == INSTANT_COMPLETE_NEVER);
-}
-
-bool InstantController::CommitIfPossible(InstantCommitType type) {
-  if (!extended_enabled_ && !instant_enabled_)
-    return false;
-
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "CommitIfPossible: type=%d last_omnibox_text_='%s' "
-      "last_match_was_search_=%d instant_tab_=%d", type,
-      UTF16ToUTF8(last_omnibox_text_).c_str(), last_match_was_search_,
-      instant_tab_ != NULL));
-
-  // If we are on an already committed search results page, send a submit event
-  // to the page, but otherwise, nothing else to do.
-  if (instant_tab_) {
-    if (type == INSTANT_COMMIT_PRESSED_ENTER &&
-        (last_match_was_search_ ||
-         last_suggestion_.behavior == INSTANT_COMPLETE_NEVER)) {
-      EnsureSearchTermsAreSet(instant_tab_->contents(), last_omnibox_text_);
-      instant_tab_->Submit(last_omnibox_text_);
-      instant_tab_->contents()->GetView()->Focus();
-      return true;
-    }
-    return false;
-  }
-
-  if (!IsPreviewingSearchResults() && type != INSTANT_COMMIT_NAVIGATED)
-    return false;
-
-  // There may re-entrance here, from the call to browser_->CommitInstant below,
-  // which can cause a TabDeactivated notification which gets back here.
-  // In this case, overlay_->ReleaseContents() was called already.
-  if (!GetPreviewContents())
-    return false;
-
-  // Never commit the local omnibox.
-  if (overlay_->IsUsingLocalPreview())
-    return false;
-
-  if (type == INSTANT_COMMIT_FOCUS_LOST)
-    overlay_->Cancel(last_omnibox_text_);
-  else if (type != INSTANT_COMMIT_NAVIGATED)
-    overlay_->Submit(last_omnibox_text_);
-
-  scoped_ptr<content::WebContents> preview = overlay_->ReleaseContents();
-
-  // If the preview page has navigated since the last Update(), we need to add
-  // the navigation to history ourselves. Else, the page will navigate after
-  // commit, and it will be added to history in the usual manner.
-  const history::HistoryAddPageArgs& last_navigation =
-      overlay_->last_navigation();
-  if (!last_navigation.url.is_empty()) {
-    content::NavigationEntry* entry = preview->GetController().GetActiveEntry();
-
-    // The last navigation should be the same as the active entry if the overlay
-    // is in search mode. During navigation, the active entry could have
-    // changed since DidCommitProvisionalLoadForFrame is called after the entry
-    // is changed.
-    // TODO(shishir): Should we commit the last navigation for
-    // INSTANT_COMMIT_NAVIGATED.
-    DCHECK(type == INSTANT_COMMIT_NAVIGATED ||
-           last_navigation.url == entry->GetURL());
-
-    // Add the page to history.
-    HistoryTabHelper* history_tab_helper =
-        HistoryTabHelper::FromWebContents(preview.get());
-    history_tab_helper->UpdateHistoryForNavigation(last_navigation);
-
-    // Update the page title.
-    history_tab_helper->UpdateHistoryPageTitle(*entry);
-  }
-
-  // Add a fake history entry with a non-Instant search URL, so that search
-  // terms extraction (for autocomplete history matches) works.
-  HistoryService* history = HistoryServiceFactory::GetForProfile(
-      Profile::FromBrowserContext(preview->GetBrowserContext()),
-      Profile::EXPLICIT_ACCESS);
-  if (history) {
-    history->AddPage(url_for_history_, base::Time::Now(), NULL, 0, GURL(),
-                     history::RedirectList(), last_transition_type_,
-                     history::SOURCE_BROWSED, false);
-  }
-
-  if (type == INSTANT_COMMIT_PRESSED_ALT_ENTER) {
-    preview->GetController().PruneAllButActive();
-  } else {
-    content::WebContents* active_tab = browser_->GetActiveWebContents();
-    AddSessionStorageHistogram(extended_enabled_, active_tab, preview.get());
-    preview->GetController().CopyStateFromAndPrune(
-        &active_tab->GetController());
-  }
-
-  if (extended_enabled_) {
-    // Adjust the search terms shown in the omnibox for this query. Hitting
-    // ENTER searches for what the user typed, so use last_omnibox_text_.
-    // Clicking on the overlay commits what is currently showing, so add in the
-    // gray text in that case.
-    if (type == INSTANT_COMMIT_FOCUS_LOST &&
-        last_suggestion_.behavior == INSTANT_COMPLETE_NEVER) {
-      // Update |last_omnibox_text_| so that the controller commits the proper
-      // query if the user focuses the omnibox and presses Enter.
-      last_omnibox_text_ += last_suggestion_.text;
-    }
-
-    EnsureSearchTermsAreSet(preview.get(), last_omnibox_text_);
-  }
-
-  // Save notification source before we release the preview.
-  content::Source<content::WebContents> notification_source(preview.get());
-
-  browser_->CommitInstant(preview.Pass(),
-                          type == INSTANT_COMMIT_PRESSED_ALT_ENTER);
-
-  content::NotificationService::current()->Notify(
-      chrome::NOTIFICATION_INSTANT_COMMITTED,
-      notification_source,
-      content::NotificationService::NoDetails());
-
-  // Hide explicitly. See comments in HideOverlay() for why.
-  model_.SetPreviewState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
-
-  // Delay deletion as we could've gotten here from an InstantOverlay method.
-  MessageLoop::current()->DeleteSoon(FROM_HERE, overlay_.release());
-
-  // Try to create another overlay immediately so that it is ready for the next
-  // user interaction.
-  EnsureOverlayIsCurrent(false);
-
-  LOG_INSTANT_DEBUG_EVENT(this, "Committed");
-  return true;
-}
-
-void InstantController::OmniboxFocusChanged(
-    OmniboxFocusState state,
-    OmniboxFocusChangeReason reason,
-    gfx::NativeView view_gaining_focus) {
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "OmniboxFocusChanged: %d to %d for reason %d", omnibox_focus_state_,
-      state, reason));
-
-  OmniboxFocusState old_focus_state = omnibox_focus_state_;
-  omnibox_focus_state_ = state;
-  if (!extended_enabled_ && !instant_enabled_)
-    return;
-
-  // Tell the page if the key capture mode changed unless the focus state
-  // changed because of TYPING. This is because in that case, the browser hasn't
-  // really stopped capturing key strokes.
-  //
-  // (More practically, if we don't do this check, the page would receive
-  // onkeycapturechange before the corresponding onchange, and the page would
-  // have no way of telling whether the keycapturechange happened because of
-  // some actual user action or just because they started typing.)
-  if (extended_enabled_ && GetPreviewContents() &&
-      reason != OMNIBOX_FOCUS_CHANGE_TYPING) {
-    const bool is_key_capture_enabled =
-        omnibox_focus_state_ == OMNIBOX_FOCUS_INVISIBLE;
-    if (overlay_)
-      overlay_->KeyCaptureChanged(is_key_capture_enabled);
-    if (instant_tab_)
-      instant_tab_->KeyCaptureChanged(is_key_capture_enabled);
-  }
-
-  // If focus went from outside the omnibox to the omnibox, preload the default
-  // search engine, in anticipation of the user typing a query. If the reverse
-  // happened, commit or discard the preview.
-  if (state != OMNIBOX_FOCUS_NONE && old_focus_state == OMNIBOX_FOCUS_NONE) {
-    // On explicit user actions, ignore the Instant blacklist.
-    EnsureOverlayIsCurrent(reason == OMNIBOX_FOCUS_CHANGE_EXPLICIT);
-  } else if (state == OMNIBOX_FOCUS_NONE &&
-             old_focus_state != OMNIBOX_FOCUS_NONE) {
-    OmniboxLostFocus(view_gaining_focus);
-  }
-}
-
-void InstantController::SearchModeChanged(
-    const chrome::search::Mode& old_mode,
-    const chrome::search::Mode& new_mode) {
-  if (!extended_enabled_)
-    return;
-
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "SearchModeChanged: [origin:mode] %d:%d to %d:%d", old_mode.origin,
-      old_mode.mode, new_mode.origin, new_mode.mode));
-
-  search_mode_ = new_mode;
-  if (!new_mode.is_search_suggestions())
-    HideOverlay();
-
-  ResetInstantTab();
-}
-
-void InstantController::ActiveTabChanged() {
-  if (!extended_enabled_ && !instant_enabled_)
-    return;
-
-  LOG_INSTANT_DEBUG_EVENT(this, "ActiveTabChanged");
-
-  // When switching tabs, always hide the preview.
-  HideOverlay();
-
-  if (extended_enabled_)
-    ResetInstantTab();
-}
-
-void InstantController::TabDeactivated(content::WebContents* contents) {
-  LOG_INSTANT_DEBUG_EVENT(this, "TabDeactivated");
-  if (extended_enabled_ && !contents->IsBeingDestroyed())
-    CommitIfPossible(INSTANT_COMMIT_FOCUS_LOST);
-}
-
-void InstantController::SetInstantEnabled(bool instant_enabled,
-                                          bool use_local_preview_only) {
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "SetInstantEnabled: instant_enabled=%d, use_local_preview_only=%d",
-      instant_enabled, use_local_preview_only));
-
-  // Non extended mode does not care about |use_local_preview_only|.
-  if (instant_enabled == instant_enabled_ &&
-      (!extended_enabled_ ||
-       use_local_preview_only == use_local_preview_only_)) {
-    return;
-  }
-
-  instant_enabled_ = instant_enabled;
-  use_local_preview_only_ = use_local_preview_only;
-  HideInternal();
-  overlay_.reset();
-  if (extended_enabled_ || instant_enabled_)
-    EnsureOverlayIsCurrent(false);
-  if (extended_enabled_)
-    ResetNTP();
-  if (instant_tab_)
-    instant_tab_->SetDisplayInstantResults(instant_enabled_);
-}
-
-void InstantController::ThemeChanged(const ThemeBackgroundInfo& theme_info) {
-  if (!extended_enabled_)
-    return;
-
-  if (overlay_)
-    overlay_->SendThemeBackgroundInfo(theme_info);
-  if (ntp_)
-    ntp_->SendThemeBackgroundInfo(theme_info);
-  if (instant_tab_)
-    instant_tab_->SendThemeBackgroundInfo(theme_info);
-}
-
-void InstantController::SwappedOverlayContents() {
-  model_.SetPreviewContents(GetPreviewContents());
-}
-
-void InstantController::FocusedOverlayContents() {
-#if defined(USE_AURA)
-  // On aura the omnibox only receives a focus lost if we initiate the focus
-  // change. This does that.
-  if (!model_.mode().is_default())
-    browser_->InstantPreviewFocused();
-#endif
-}
-
-void InstantController::ReloadOverlayIfStale() {
-  // The local popup is never stale.
-  if (overlay_ && overlay_->IsUsingLocalPreview())
-    return;
-
-  // If the preview is showing or the omnibox has focus, don't delete the
-  // overlay. It will get refreshed the next time the preview is hidden or the
-  // omnibox loses focus.
-  if ((!overlay_ || overlay_->is_stale()) &&
-      omnibox_focus_state_ == OMNIBOX_FOCUS_NONE &&
-      model_.mode().is_default()) {
-    overlay_.reset();
-    EnsureOverlayIsCurrent(false);
-  }
-}
-
-void InstantController::LogDebugEvent(const std::string& info) const {
-  DVLOG(1) << info;
-
-  debug_events_.push_front(std::make_pair(
-      base::Time::Now().ToInternalValue(), info));
-  static const size_t kMaxDebugEventSize = 2000;
-  if (debug_events_.size() > kMaxDebugEventSize)
-    debug_events_.pop_back();
-}
-
-void InstantController::DeleteMostVisitedItem(const GURL& url) {
-  history::TopSites* top_sites = browser_->profile()->GetTopSites();
-  if (!top_sites)
-    return;
-
-  top_sites->AddBlacklistedURL(url);
-}
-
-void InstantController::UndoMostVisitedDeletion(const GURL& url) {
-  history::TopSites* top_sites = browser_->profile()->GetTopSites();
-  if (!top_sites)
-    return;
-
-  top_sites->RemoveBlacklistedURL(url);
-}
-
-void InstantController::UndoAllMostVisitedDeletions() {
-  history::TopSites* top_sites = browser_->profile()->GetTopSites();
-  if (!top_sites)
-    return;
-
-  top_sites->ClearBlacklistedURLs();
-}
-
-void InstantController::Observe(int type,
-                                const content::NotificationSource& source,
-                                const content::NotificationDetails& details) {
-  DCHECK_EQ(type, chrome::NOTIFICATION_TOP_SITES_CHANGED);
-  RequestMostVisitedItems();
-}
-
-// TODO(shishir): We assume that the WebContent's current RenderViewHost is the
-// RenderViewHost being created which is not always true. Fix this.
-void InstantController::InstantPageRenderViewCreated(
-    const content::WebContents* contents) {
-  if (!extended_enabled_)
-    return;
-
-  // Update theme info so that the page picks it up.
-  browser_->UpdateThemeInfo(false);
-
-  // Ensure the searchbox API has the correct initial state.
-  if (IsContentsFrom(overlay(), contents)) {
-    overlay_->SetDisplayInstantResults(instant_enabled_);
-    overlay_->KeyCaptureChanged(
-        omnibox_focus_state_ == OMNIBOX_FOCUS_INVISIBLE);
-    overlay_->SetOmniboxBounds(omnibox_bounds_);
-    overlay_->InitializeFonts();
-  } else if (IsContentsFrom(ntp(), contents)) {
-    ntp_->SetDisplayInstantResults(instant_enabled_);
-    ntp_->SetOmniboxBounds(omnibox_bounds_);
-    ntp_->InitializeFonts();
-  } else {
-    NOTREACHED();
-  }
-  StartListeningToMostVisitedChanges();
-}
-
-void InstantController::InstantSupportDetermined(
-    const content::WebContents* contents,
-    bool supports_instant) {
-  if (IsContentsFrom(instant_tab(), contents)) {
-    if (!supports_instant)
-      MessageLoop::current()->DeleteSoon(FROM_HERE, instant_tab_.release());
-  } else if (IsContentsFrom(ntp(), contents)) {
-    if (supports_instant)
-      RemoveFromBlacklist(ntp_->instant_url());
-    else
-      BlacklistAndResetNTP();
-
-    content::NotificationService::current()->Notify(
-        chrome::NOTIFICATION_INSTANT_NTP_SUPPORT_DETERMINED,
-        content::Source<InstantController>(this),
-        content::NotificationService::NoDetails());
-
-  } else if (IsContentsFrom(overlay(), contents)) {
-    if (supports_instant)
-      RemoveFromBlacklist(overlay_->instant_url());
-    else
-      BlacklistAndResetOverlay();
-
-    content::NotificationService::current()->Notify(
-        chrome::NOTIFICATION_INSTANT_OVERLAY_SUPPORT_DETERMINED,
-        content::Source<InstantController>(this),
-        content::NotificationService::NoDetails());
-  }
-}
-
-void InstantController::InstantPageRenderViewGone(
-    const content::WebContents* contents) {
-  if (IsContentsFrom(overlay(), contents))
-    BlacklistAndResetOverlay();
-  else if (IsContentsFrom(ntp(), contents))
-    BlacklistAndResetNTP();
-  else
-    NOTREACHED();
-}
-
-void InstantController::InstantPageAboutToNavigateMainFrame(
-    const content::WebContents* contents,
-    const GURL& url) {
-  DCHECK(IsContentsFrom(overlay(), contents));
-
-  // If the page does not yet support instant, we allow redirects and other
-  // navigations to go through since the instant URL can redirect - e.g. to
-  // country specific pages.
-  if (!overlay_->supports_instant())
-    return;
-
-  GURL instant_url(overlay_->instant_url());
-
-  // If we are navigating to the instant URL, do nothing.
-  if (url == instant_url)
-    return;
-
-  // Commit the navigation if either:
-  //  - The page is in NTP mode (so it could only navigate on a user click) or
-  //  - The page is not in NTP mode and we are navigating to a URL with a
-  //    different host or path than the instant URL. This enables the instant
-  //    page when it is showing search results to change the query parameters
-  //    and fragments of the URL without it navigating.
-  if (model_.mode().is_ntp() ||
-      (url.host() != instant_url.host() || url.path() != instant_url.path())) {
-    CommitIfPossible(INSTANT_COMMIT_NAVIGATED);
-  }
-}
-
-void InstantController::SetSuggestions(
-    const content::WebContents* contents,
-    const std::vector<InstantSuggestion>& suggestions) {
-  LOG_INSTANT_DEBUG_EVENT(this, "SetSuggestions");
-
-  // Ignore if the message is from an unexpected source.
-  if (IsContentsFrom(ntp(), contents))
-    return;
-  if (instant_tab_ && !IsContentsFrom(instant_tab(), contents))
-    return;
-  if (IsContentsFrom(overlay(), contents) &&
-      !allow_preview_to_show_search_suggestions_)
-    return;
-
-  InstantSuggestion suggestion;
-  if (!suggestions.empty())
-    suggestion = suggestions[0];
-
-  if (instant_tab_ && search_mode_.is_search_results() &&
-      suggestion.behavior == INSTANT_COMPLETE_REPLACE) {
-    // Update |last_omnibox_text_| so that the controller commits the proper
-    // query if the user focuses the omnibox and presses Enter.
-    last_omnibox_text_ = suggestion.text;
-    last_suggestion_ = InstantSuggestion();
-    last_match_was_search_ = suggestion.type == INSTANT_SUGGESTION_SEARCH;
-    // This means a committed page in state search called setValue(). We should
-    // update the omnibox to reflect what the search page says.
-    browser_->SetInstantSuggestion(suggestion);
-    return;
-  }
-
-  // Ignore if we are not currently accepting search suggestions.
-  if (!search_mode_.is_search_suggestions() || last_omnibox_text_.empty())
-    return;
-
-  if (suggestion.behavior == INSTANT_COMPLETE_REPLACE) {
-    // We don't get an Update() when changing the omnibox due to a REPLACE
-    // suggestion (so that we don't inadvertently cause the preview to change
-    // what it's showing, as the user arrows up/down through the page-provided
-    // suggestions). So, update these state variables here.
-    last_omnibox_text_ = suggestion.text;
-    last_suggestion_ = InstantSuggestion();
-    last_match_was_search_ = suggestion.type == INSTANT_SUGGESTION_SEARCH;
-    LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-        "ReplaceSuggestion text='%s' type=%d",
-        UTF16ToUTF8(suggestion.text).c_str(), suggestion.type));
-    browser_->SetInstantSuggestion(suggestion);
-  } else {
-    bool is_valid_suggestion = true;
-
-    // If the page is trying to set inline autocompletion in verbatim mode,
-    // instead try suggesting the exact omnibox text. This makes the omnibox
-    // interpret user text as an URL if possible while preventing unwanted
-    // autocompletion during backspacing.
-    if (suggestion.behavior == INSTANT_COMPLETE_NOW && last_verbatim_)
-      suggestion.text = last_omnibox_text_;
-
-    // Suggestion text should be a full URL for URL suggestions, or the
-    // completion of a query for query suggestions.
-    if (suggestion.type == INSTANT_SUGGESTION_URL) {
-      // If the suggestion is not a valid URL, perhaps it's something like
-      // "foo.com". Try prefixing "http://". If it still isn't valid, drop it.
-      if (!GURL(suggestion.text).is_valid()) {
-        suggestion.text.insert(0, ASCIIToUTF16("http://"));
-        if (!GURL(suggestion.text).is_valid())
-          is_valid_suggestion = false;
-      }
-    } else if (StartsWith(suggestion.text, last_omnibox_text_, true)) {
-      // The user typed an exact prefix of the suggestion.
-      suggestion.text.erase(0, last_omnibox_text_.size());
-    } else if (!NormalizeAndStripPrefix(&suggestion.text, last_omnibox_text_)) {
-      // Unicode normalize and case-fold the user text and suggestion. If the
-      // user text is a prefix, suggest the normalized, case-folded completion;
-      // for instance, if the user types 'i' and the suggestion is 'INSTANT',
-      // suggest 'nstant'. Otherwise, the user text really isn't a prefix, so
-      // suggest nothing.
-      is_valid_suggestion = false;
-    }
-
-    // Don't suggest gray text if there already was inline autocompletion.
-    // http://crbug.com/162303
-    if (suggestion.behavior == INSTANT_COMPLETE_NEVER &&
-        last_omnibox_text_has_inline_autocompletion_)
-      is_valid_suggestion = false;
-
-    if (is_valid_suggestion) {
-      last_suggestion_ = suggestion;
-      LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-          "SetInstantSuggestion: text='%s' behavior=%d",
-          UTF16ToUTF8(suggestion.text).c_str(), suggestion.behavior));
-      browser_->SetInstantSuggestion(suggestion);
-    } else {
-      last_suggestion_ = InstantSuggestion();
-    }
-  }
-
-  // Extended mode pages will call ShowOverlay() when they are ready.
-  if (!extended_enabled_)
-    ShowOverlay(INSTANT_SHOWN_QUERY_SUGGESTIONS, 100, INSTANT_SIZE_PERCENT);
-}
-
-void InstantController::ShowInstantOverlay(const content::WebContents* contents,
-                                           InstantShownReason reason,
-                                           int height,
-                                           InstantSizeUnits units) {
-  if (extended_enabled_ && IsContentsFrom(overlay(), contents))
-    ShowOverlay(reason, height, units);
-}
-
-void InstantController::StartCapturingKeyStrokes(
-    const content::WebContents* contents) {
-  if (!extended_enabled_)
-    return;
-
-  DCHECK(IsContentsFrom(instant_tab(), contents));
-  browser_->FocusOmniboxInvisibly();
-}
-
-void InstantController::StopCapturingKeyStrokes(
-    content::WebContents* contents) {
-  // Nothing to do if omnibox doesn't have invisible focus.
-  if (!extended_enabled_ || omnibox_focus_state_ != OMNIBOX_FOCUS_INVISIBLE)
-    return;
-
-  DCHECK(IsContentsFrom(instant_tab(), contents));
-  contents->GetView()->Focus();
-}
-
-void InstantController::NavigateToURL(const content::WebContents* contents,
-                                      const GURL& url,
-                                      content::PageTransition transition,
-                                      WindowOpenDisposition disposition) {
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "NavigateToURL: url='%s'", url.spec().c_str()));
-
-  // TODO(samarth): handle case where contents are no longer "active" (e.g. user
-  // has switched tabs).
-  if (!extended_enabled_)
-    return;
-  if (overlay_)
-    HideOverlay();
-  browser_->OpenURL(url, transition, disposition);
-}
-
-void InstantController::OmniboxLostFocus(gfx::NativeView view_gaining_focus) {
-  // If the preview is showing custom NTP content, don't hide it, commit it
-  // (no matter where the user clicked) or try to recreate it.
-  if (model_.mode().is_ntp())
-    return;
-
-  if (model_.mode().is_default()) {
-    // Correct search terms if the user clicked on the committed results page
-    // while showing an autocomplete suggestion
-    if (instant_tab_ && !last_suggestion_.text.empty() &&
-        last_suggestion_.behavior == INSTANT_COMPLETE_NEVER &&
-        IsViewInContents(GetViewGainingFocus(view_gaining_focus),
-                         instant_tab_->contents())) {
-      // Commit the omnibox's suggested grey text as if the user had typed it.
-      browser_->CommitSuggestedText(true);
-
-      // Update the state so that next query from hitting Enter from the
-      // omnibox is correct.
-      last_omnibox_text_ += last_suggestion_.text;
-      last_suggestion_ = InstantSuggestion();
-    }
-    // If the preview is not showing at all, recreate it if it's stale.
-    ReloadOverlayIfStale();
-    MaybeSwitchToRemoteOverlay();
-    return;
-  }
-
-  // The preview is showing search suggestions. If GetPreviewContents() is NULL,
-  // we are in the commit path. Don't do anything.
-  if (!GetPreviewContents())
-    return;
-
-#if defined(OS_MACOSX)
-  // TODO(sreeram): See if Mac really needs this special treatment.
-  if (!overlay_->is_pointer_down_from_activate())
-    HideOverlay();
-#else
-  if (IsFullHeight(model_))
-    CommitIfPossible(INSTANT_COMMIT_FOCUS_LOST);
-  else if (!IsViewInContents(GetViewGainingFocus(view_gaining_focus),
-                             overlay_->contents()))
-    HideOverlay();
-#endif
-}
-
-void InstantController::ResetNTP() {
-  ntp_.reset();
-  std::string instant_url;
-  if (!GetInstantURL(browser_->profile(), false, &instant_url))
-    return;
-
-  ntp_.reset(new InstantNTP(this, instant_url));
-  ntp_->InitContents(browser_->profile(), browser_->GetActiveWebContents(),
-                     base::Bind(&InstantController::ResetNTP,
-                                base::Unretained(this)));
-}
-
-bool InstantController::EnsureOverlayIsCurrent(bool ignore_blacklist) {
-  // If there's no active tab, the browser is closing.
-  const content::WebContents* active_tab = browser_->GetActiveWebContents();
-  if (!active_tab)
-    return false;
-
-  Profile* profile = Profile::FromBrowserContext(
-      active_tab->GetBrowserContext());
-  std::string instant_url;
-  if (!GetInstantURL(profile, ignore_blacklist, &instant_url)) {
-    // If we are in extended mode, fallback to the local popup.
-    if (extended_enabled_)
-      instant_url = chrome::search::kLocalOmniboxPopupURL;
-    else
-      return false;
-  }
-
-  if (!overlay_ || overlay_->instant_url() != instant_url)
-    CreateOverlay(instant_url, active_tab);
-
-  return true;
-}
-
-void InstantController::CreateOverlay(const std::string& instant_url,
-                                      const content::WebContents* active_tab) {
-  HideInternal();
-  overlay_.reset(new InstantOverlay(this, instant_url));
-  overlay_->InitContents(browser_->profile(), active_tab);
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "CreateOverlay: instant_url='%s'", instant_url.c_str()));
-}
-
-void InstantController::MaybeSwitchToRemoteOverlay() {
-  if (!overlay_ || omnibox_focus_state_ != OMNIBOX_FOCUS_NONE ||
-      !model_.mode().is_default()) {
-    return;
-  }
-
-  EnsureOverlayIsCurrent(false);
-}
-
-void InstantController::ResetInstantTab() {
-  // Do not wire up the InstantTab if instant should only use local previews, to
-  // prevent it from sending data to the page.
-  if (!search_mode_.is_origin_default() && !use_local_preview_only_) {
-    content::WebContents* active_tab = browser_->GetActiveWebContents();
-    if (!instant_tab_ || active_tab != instant_tab_->contents()) {
-      instant_tab_.reset(new InstantTab(this));
-      instant_tab_->Init(active_tab);
-      // Update theme info for this tab.
-      browser_->UpdateThemeInfo(false);
-      instant_tab_->SetDisplayInstantResults(instant_enabled_);
-      instant_tab_->SetOmniboxBounds(omnibox_bounds_);
-      instant_tab_->InitializeFonts();
-      StartListeningToMostVisitedChanges();
-      instant_tab_->KeyCaptureChanged(
-          omnibox_focus_state_ == OMNIBOX_FOCUS_INVISIBLE);
-    }
-
-    // Hide the |overlay_| since we are now using |instant_tab_| instead.
-    HideOverlay();
-  } else {
-    instant_tab_.reset();
-  }
-}
-
-void InstantController::HideOverlay() {
-  HideInternal();
-  ReloadOverlayIfStale();
-  MaybeSwitchToRemoteOverlay();
-}
-
-void InstantController::HideInternal() {
-  LOG_INSTANT_DEBUG_EVENT(this, "Hide");
-
-  // If GetPreviewContents() returns NULL, either we're already in the desired
-  // MODE_DEFAULT state, or we're in the commit path. For the latter, don't
-  // change the state just yet; else we may hide the preview unnecessarily.
-  // Instead, the state will be set correctly after the commit is done.
-  if (GetPreviewContents()) {
-    model_.SetPreviewState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
-    allow_preview_to_show_search_suggestions_ = false;
-
-    // Send a message asking the preview to clear out old results.
-    overlay_->Update(string16(), 0, 0, true);
-  }
-
-  // Clear the first interaction timestamp for later use.
-  first_interaction_time_ = base::Time();
-}
-
-void InstantController::ShowOverlay(InstantShownReason reason,
-                                    int height,
-                                    InstantSizeUnits units) {
-  // If we are on a committed search results page, the |overlay_| is not in use.
-  if (instant_tab_)
-    return;
-
-  LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "Show: reason=%d height=%d units=%d", reason, height, units));
-
-  // INSTANT_SHOWN_CUSTOM_NTP_CONTENT is no longer supported.
-  // TODO(samarth): remove once the server has been updated.
-  if (reason == INSTANT_SHOWN_CUSTOM_NTP_CONTENT)
-    return;
-
-  // Must have updated omnibox after the last HideOverlay() to show suggestions.
-  if (reason == INSTANT_SHOWN_QUERY_SUGGESTIONS &&
-      !allow_preview_to_show_search_suggestions_)
-    return;
-
-  // The page is trying to hide itself. Hide explicitly (i.e., don't use
-  // HideOverlay()) so that it can change its mind.
-  if (height == 0) {
-    model_.SetPreviewState(chrome::search::Mode(), 0, INSTANT_SIZE_PERCENT);
-    return;
-  }
-
-  // If the preview is being shown for the first time since the user started
-  // typing, record a histogram value.
-  if (!first_interaction_time_.is_null() && model_.mode().is_default()) {
-    base::TimeDelta delta = base::Time::Now() - first_interaction_time_;
-    UMA_HISTOGRAM_TIMES("Instant.TimeToFirstShow", delta);
-  }
-
-  // Show at 100% height except in the following cases:
-  // - The local omnibox popup is being loaded.
-  // - Instant is disabled. The page needs to be able to show only a dropdown.
-  // - The page wants to show custom NTP content.
-  // - The page is over a website other than search or an NTP, and is not
-  //   already showing at 100% height.
-  if (overlay_->IsUsingLocalPreview() || !instant_enabled_ ||
-      reason == INSTANT_SHOWN_CUSTOM_NTP_CONTENT ||
-      (search_mode_.is_origin_default() && !IsFullHeight(model_)))
-    model_.SetPreviewState(search_mode_, height, units);
-  else
-    model_.SetPreviewState(search_mode_, 100, INSTANT_SIZE_PERCENT);
-
-  // If the overlay is being shown at full height and the omnibox is not
-  // focused, commit right away.
-  if (IsFullHeight(model_) && omnibox_focus_state_ == OMNIBOX_FOCUS_NONE)
-    CommitIfPossible(INSTANT_COMMIT_FOCUS_LOST);
-}
-
-void InstantController::SendPopupBoundsToPage() {
-  if (last_popup_bounds_ == popup_bounds_ || !overlay_ ||
-      overlay_->is_pointer_down_from_activate())
-    return;
-
-  last_popup_bounds_ = popup_bounds_;
-  gfx::Rect preview_bounds = browser_->GetInstantBounds();
-  gfx::Rect intersection = gfx::IntersectRects(popup_bounds_, preview_bounds);
-
-  // Translate into window coordinates.
-  if (!intersection.IsEmpty()) {
-    intersection.Offset(-preview_bounds.origin().x(),
-                        -preview_bounds.origin().y());
-  }
-
-  // In the current Chrome UI, these must always be true so they sanity check
-  // the above operations. In a future UI, these may be removed or adjusted.
-  // There is no point in sanity-checking |intersection.y()| because the omnibox
-  // can be placed anywhere vertically relative to the preview (for example, in
-  // Mac fullscreen mode, the omnibox is fully enclosed by the preview bounds).
-  DCHECK_LE(0, intersection.x());
-  DCHECK_LE(0, intersection.width());
-  DCHECK_LE(0, intersection.height());
-
-  overlay_->SetPopupBounds(intersection);
-}
-
-bool InstantController::GetInstantURL(Profile* profile,
-                                      bool ignore_blacklist,
-                                      std::string* instant_url) const {
-  DCHECK(profile);
-  instant_url->clear();
-
-  if (extended_enabled_ && use_local_preview_only_) {
-    *instant_url = chrome::search::kLocalOmniboxPopupURL;
-    return true;
-  }
-
-  const TemplateURL* template_url = TemplateURLServiceFactory::GetForProfile(
-      profile)->GetDefaultSearchProvider();
-
-  if (!template_url) {
-    LOG_INSTANT_DEBUG_EVENT(this, "GetInstantURL: No template URL");
-    return false;
-  }
-
-  CommandLine* command_line = CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(switches::kInstantURL))
-    *instant_url = command_line->GetSwitchValueASCII(switches::kInstantURL);
-
-  if (instant_url->empty()) {
-    const TemplateURLRef& instant_url_ref = template_url->instant_url_ref();
-    if (!instant_url_ref.IsValid()) {
-      LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-          "GetInstantURL: TemplateRef invalid: url=%s",
-          template_url->instant_url().c_str()));
-      return false;
-    }
-
-    // Even if the URL template doesn't have search terms, it may have other
-    // components (such as {google:baseURL}) that need to be replaced.
-    *instant_url = instant_url_ref.ReplaceSearchTerms(
-        TemplateURLRef::SearchTermsArgs(string16()));
-
-    // Extended mode should always use HTTPS. TODO(sreeram): This section can be
-    // removed if TemplateURLs supported "https://{google:host}/..." instead of
-    // only supporting "{google:baseURL}...".
-    if (extended_enabled_) {
-      GURL url_obj(*instant_url);
-      if (!url_obj.is_valid()) {
-        LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-            "GetInstantURL: Instant URL invalid: url=%s",
-            url_obj.possibly_invalid_spec().c_str()));
-        return false;
-      }
-
-      // Extended mode won't work properly unless the TemplateURL supports the
-      // param to enable it on the server.
-      if (!template_url->HasSearchTermsReplacementKey(url_obj)) {
-        LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-            "GetInstantURL: No search terms replacement key: url=%s",
-            url_obj.spec().c_str()));
-        return false;
-      }
-
-      if (!url_obj.SchemeIsSecure()) {
-        std::string new_scheme = "https";
-        std::string new_port = "443";
-        GURL::Replacements secure;
-        secure.SetSchemeStr(new_scheme);
-        secure.SetPortStr(new_port);
-        url_obj = url_obj.ReplaceComponents(secure);
-
-        if (!url_obj.is_valid()) {
-          LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-              "GetInstantURL: HTTPS URL invalid: url=%s",
-              url_obj.possibly_invalid_spec().c_str()));
-          return false;
-        }
-
-        *instant_url = url_obj.spec();
-      }
-    }
-  }
-
-  if (!ignore_blacklist) {
-    std::map<std::string, int>::const_iterator iter =
-        blacklisted_urls_.find(*instant_url);
-    if (iter != blacklisted_urls_.end() &&
-        iter->second > kMaxInstantSupportFailures) {
-      RecordEventHistogram(INSTANT_CONTROLLER_EVENT_URL_BLOCKED_BY_BLACKLIST);
-      LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-          "GetInstantURL: Instant URL blacklisted: url=%s",
-          instant_url->c_str()));
-      return false;
-    }
-  }
-
-  return true;
-}
-
-void InstantController::BlacklistAndResetNTP() {
-  ++blacklisted_urls_[ntp_->instant_url()];
-  RecordEventHistogram(INSTANT_CONTROLLER_EVENT_URL_ADDED_TO_BLACKLIST);
-  delete ntp_->ReleaseContents().release();
-  MessageLoop::current()->DeleteSoon(FROM_HERE, ntp_.release());
-  ResetNTP();
-}
-
-void InstantController::BlacklistAndResetOverlay() {
-  ++blacklisted_urls_[overlay_->instant_url()];
-  RecordEventHistogram(INSTANT_CONTROLLER_EVENT_URL_ADDED_TO_BLACKLIST);
-  HideInternal();
-  delete overlay_->ReleaseContents().release();
-  MessageLoop::current()->DeleteSoon(FROM_HERE, overlay_.release());
-  EnsureOverlayIsCurrent(false);
-}
-
-void InstantController::RemoveFromBlacklist(const std::string& url) {
-  if (blacklisted_urls_.erase(url)) {
-    RecordEventHistogram(INSTANT_CONTROLLER_EVENT_URL_REMOVED_FROM_BLACKLIST);
-  }
-}
-
-void InstantController::StartListeningToMostVisitedChanges() {
-  history::TopSites* top_sites = browser_->profile()->GetTopSites();
-  if (top_sites) {
-    if (!registrar_.IsRegistered(
-      this, chrome::NOTIFICATION_TOP_SITES_CHANGED,
-      content::Source<history::TopSites>(top_sites))) {
-      // TopSites updates itself after a delay. This is especially noticable
-      // when your profile is empty. Ask TopSites to update itself when we're
-      // about to show the new tab page.
-      top_sites->SyncWithHistory();
-
-      RequestMostVisitedItems();
-
-      // Register for notification when TopSites changes.
-      registrar_.Add(this, chrome::NOTIFICATION_TOP_SITES_CHANGED,
-                     content::Source<history::TopSites>(top_sites));
-    } else {
-      // We are already registered, so just get and send the most visited data.
-      RequestMostVisitedItems();
-    }
-  }
-}
-
-void InstantController::RequestMostVisitedItems() {
-  history::TopSites* top_sites = browser_->profile()->GetTopSites();
-  if (top_sites) {
-    top_sites->GetMostVisitedURLs(
-        base::Bind(&InstantController::OnMostVisitedItemsReceived,
-                   weak_ptr_factory_.GetWeakPtr()));
-  }
-}
-
-void InstantController::OnMostVisitedItemsReceived(
-    const history::MostVisitedURLList& data) {
-  std::vector<MostVisitedItem> most_visited_items;
-  for (size_t i = 0; i < data.size(); i++) {
-    const history::MostVisitedURL& url = data[i];
-
-    MostVisitedItem item;
-    item.url = url.url;
-    item.title = url.title;
-
-    most_visited_items.push_back(item);
-  }
-  SendMostVisitedItems(most_visited_items);
-}
-
-void InstantController::SendMostVisitedItems(
-    const std::vector<MostVisitedItem>& items) {
-  if (overlay_)
-    overlay_->SendMostVisitedItems(items);
-  if (ntp_)
-    ntp_->SendMostVisitedItems(items);
-  if (instant_tab_)
-    instant_tab_->SendMostVisitedItems(items);
-  content::NotificationService::current()->Notify(
-      chrome::NOTIFICATION_INSTANT_SENT_MOST_VISITED_ITEMS,
-      content::Source<InstantController>(this),
-      content::NotificationService::NoDetails());
-}