chrome/browser/ui/browser_navigator.cc

   1 // Copyright (c) 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/browser_navigator.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/command_line.h"
  10 #include "base/prefs/pref_service.h"
  11 #include "base/strings/stringprintf.h"
  12 #include "base/strings/utf_string_conversions.h"
  13 #include "chrome/browser/browser_about_handler.h"
  14 #include "chrome/browser/chrome_notification_types.h"
  15 #include "chrome/browser/extensions/tab_helper.h"
  16 #include "chrome/browser/google/google_url_tracker.h"
  17 #include "chrome/browser/prefs/incognito_mode_prefs.h"
  18 #include "chrome/browser/prerender/prerender_manager.h"
  19 #include "chrome/browser/prerender/prerender_manager_factory.h"
  20 #include "chrome/browser/prerender/prerender_util.h"
  21 #include "chrome/browser/profiles/profile.h"
  22 #include "chrome/browser/tab_contents/tab_util.h"
  23 #include "chrome/browser/ui/browser.h"
  24 #include "chrome/browser/ui/browser_finder.h"
  25 #include "chrome/browser/ui/browser_instant_controller.h"
  26 #include "chrome/browser/ui/browser_window.h"
  27 #include "chrome/browser/ui/host_desktop.h"
  28 #include "chrome/browser/ui/omnibox/location_bar.h"
  29 #include "chrome/browser/ui/search/instant_search_prerenderer.h"
  30 #include "chrome/browser/ui/singleton_tabs.h"
  31 #include "chrome/browser/ui/status_bubble.h"
  32 #include "chrome/browser/ui/tab_helpers.h"
  33 #include "chrome/browser/ui/tabs/tab_strip_model.h"
  34 #include "chrome/browser/web_applications/web_app.h"
  35 #include "chrome/common/pref_names.h"
  36 #include "chrome/common/url_constants.h"
  37 #include "content/public/browser/browser_url_handler.h"
  38 #include "content/public/browser/navigation_entry.h"
  39 #include "content/public/browser/notification_service.h"
  40 #include "content/public/browser/render_view_host.h"
  41 #include "content/public/browser/web_contents.h"
  42 #include "content/public/browser/web_contents_view.h"
  43 #include "extensions/browser/extension_registry.h"
  44 #include "extensions/common/extension.h"
  45 #include "extensions/common/extension_set.h"
  46
  47 #if defined(USE_ASH)
  48 #include "chrome/browser/ui/ash/multi_user/multi_user_window_manager.h"
  49 #endif
  50 #if defined(USE_AURA)
  51 #include "ui/aura/window.h"
  52 #endif
  53
  54 using content::GlobalRequestID;
  55 using content::NavigationController;
  56 using content::WebContents;
  57
  58 class BrowserNavigatorWebContentsAdoption {
  59  public:
  60   static void AttachTabHelpers(content::WebContents* contents) {
  61     TabHelpers::AttachTabHelpers(contents);
  62   }
  63 };
  64
  65 namespace {
  66
  67 // Returns true if the specified Browser can open tabs. Not all Browsers support
  68 // multiple tabs, such as app frames and popups. This function returns false for
  69 // those types of Browser.
  70 bool WindowCanOpenTabs(Browser* browser) {
  71   return browser->CanSupportWindowFeature(Browser::FEATURE_TABSTRIP) ||
  72       browser->tab_strip_model()->empty();
  73 }
  74
  75 // Finds an existing Browser compatible with |profile|, making a new one if no
  76 // such Browser is located.
  77 Browser* GetOrCreateBrowser(Profile* profile,
  78                             chrome::HostDesktopType host_desktop_type) {
  79   Browser* browser = chrome::FindTabbedBrowser(profile, false,
  80                                                host_desktop_type);
  81   return browser ? browser : new Browser(
  82       Browser::CreateParams(profile, host_desktop_type));
  83 }
  84
  85 // Change some of the navigation parameters based on the particular URL.
  86 // Currently this applies to some chrome:// pages which we always want to open
  87 // in a non-incognito window. Note that even though a ChromeOS guest session is
  88 // technically an incognito window, these URLs are allowed.
  89 // Returns true on success. Otherwise, if changing params leads the browser into
  90 // an erroneous state, returns false.
  91 bool AdjustNavigateParamsForURL(chrome::NavigateParams* params) {
  92   if (params->target_contents != NULL ||
  93       chrome::IsURLAllowedInIncognito(params->url,
  94                                       params->initiating_profile) ||
  95       params->initiating_profile->IsGuestSession()) {
  96     return true;
  97   }
  98
  99   Profile* profile = params->initiating_profile;
 100
 101   if (profile->IsOffTheRecord() || params->disposition == OFF_THE_RECORD) {
 102     profile = profile->GetOriginalProfile();
 103
 104     // If incognito is forced, we punt.
 105     PrefService* prefs = profile->GetPrefs();
 106     if (prefs && IncognitoModePrefs::GetAvailability(prefs) ==
 107             IncognitoModePrefs::FORCED) {
 108       return false;
 109     }
 110
 111     params->disposition = SINGLETON_TAB;
 112     params->browser = GetOrCreateBrowser(profile, params->host_desktop_type);
 113     params->window_action = chrome::NavigateParams::SHOW_WINDOW;
 114   }
 115
 116   return true;
 117 }
 118
 119 // Returns a Browser that can host the navigation or tab addition specified in
 120 // |params|. This might just return the same Browser specified in |params|, or
 121 // some other if that Browser is deemed incompatible.
 122 Browser* GetBrowserForDisposition(chrome::NavigateParams* params) {
 123   // If no source WebContents was specified, we use the selected one from
 124   // the target browser. This must happen first, before
 125   // GetBrowserForDisposition() has a chance to replace |params->browser| with
 126   // another one.
 127   if (!params->source_contents && params->browser) {
 128     params->source_contents =
 129         params->browser->tab_strip_model()->GetActiveWebContents();
 130   }
 131
 132   Profile* profile = params->initiating_profile;
 133
 134   switch (params->disposition) {
 135     case CURRENT_TAB:
 136       if (params->browser)
 137         return params->browser;
 138       // Find a compatible window and re-execute this command in it. Otherwise
 139       // re-run with NEW_WINDOW.
 140       return GetOrCreateBrowser(profile, params->host_desktop_type);
 141     case SINGLETON_TAB:
 142     case NEW_FOREGROUND_TAB:
 143     case NEW_BACKGROUND_TAB:
 144       // See if we can open the tab in the window this navigator is bound to.
 145       if (params->browser && WindowCanOpenTabs(params->browser))
 146         return params->browser;
 147       // Find a compatible window and re-execute this command in it. Otherwise
 148       // re-run with NEW_WINDOW.
 149       return GetOrCreateBrowser(profile, params->host_desktop_type);
 150     case NEW_POPUP: {
 151       // Make a new popup window.
 152       // Coerce app-style if |source| represents an app.
 153       std::string app_name;
 154       if (!params->extension_app_id.empty()) {
 155         app_name = web_app::GenerateApplicationNameFromExtensionId(
 156             params->extension_app_id);
 157       } else if (params->browser && !params->browser->app_name().empty()) {
 158         app_name = params->browser->app_name();
 159       } else if (params->source_contents) {
 160         extensions::TabHelper* extensions_tab_helper =
 161             extensions::TabHelper::FromWebContents(params->source_contents);
 162         if (extensions_tab_helper && extensions_tab_helper->is_app()) {
 163           app_name = web_app::GenerateApplicationNameFromExtensionId(
 164               extensions_tab_helper->extension_app()->id());
 165         }
 166       }
 167       if (app_name.empty()) {
 168         Browser::CreateParams browser_params(
 169             Browser::TYPE_POPUP, profile, params->host_desktop_type);
 170         browser_params.initial_bounds = params->window_bounds;
 171         return new Browser(browser_params);
 172       }
 173
 174       return new Browser(Browser::CreateParams::CreateForApp(
 175           Browser::TYPE_POPUP, app_name, params->window_bounds, profile,
 176           params->host_desktop_type));
 177     }
 178     case NEW_WINDOW: {
 179       // Make a new normal browser window.
 180       return new Browser(Browser::CreateParams(profile,
 181                                                params->host_desktop_type));
 182     }
 183     case OFF_THE_RECORD:
 184       // Make or find an incognito window.
 185       return GetOrCreateBrowser(profile->GetOffTheRecordProfile(),
 186                                 params->host_desktop_type);
 187     // The following types all result in no navigation.
 188     case SUPPRESS_OPEN:
 189     case SAVE_TO_DISK:
 190     case IGNORE_ACTION:
 191       return NULL;
 192     default:
 193       NOTREACHED();
 194   }
 195   return NULL;
 196 }
 197
 198 // Fix disposition and other parameter values depending on prevailing
 199 // conditions.
 200 void NormalizeDisposition(chrome::NavigateParams* params) {
 201   // Calculate the WindowOpenDisposition if necessary.
 202   if (params->browser->tab_strip_model()->empty() &&
 203       (params->disposition == NEW_BACKGROUND_TAB ||
 204        params->disposition == CURRENT_TAB ||
 205        params->disposition == SINGLETON_TAB)) {
 206     params->disposition = NEW_FOREGROUND_TAB;
 207   }
 208   if (params->browser->profile()->IsOffTheRecord() &&
 209       params->disposition == OFF_THE_RECORD) {
 210     params->disposition = NEW_FOREGROUND_TAB;
 211   }
 212   if (!params->source_contents && params->disposition == CURRENT_TAB)
 213     params->disposition = NEW_FOREGROUND_TAB;
 214
 215   switch (params->disposition) {
 216     case NEW_BACKGROUND_TAB:
 217       // Disposition trumps add types. ADD_ACTIVE is a default, so we need to
 218       // remove it if disposition implies the tab is going to open in the
 219       // background.
 220       params->tabstrip_add_types &= ~TabStripModel::ADD_ACTIVE;
 221       break;
 222
 223     case NEW_WINDOW:
 224     case NEW_POPUP:
 225       // Code that wants to open a new window typically expects it to be shown
 226       // automatically.
 227       if (params->window_action == chrome::NavigateParams::NO_ACTION)
 228         params->window_action = chrome::NavigateParams::SHOW_WINDOW;
 229       // Fall-through.
 230     case NEW_FOREGROUND_TAB:
 231     case SINGLETON_TAB:
 232       params->tabstrip_add_types |= TabStripModel::ADD_ACTIVE;
 233       break;
 234
 235     default:
 236       break;
 237   }
 238 }
 239
 240 // Obtain the profile used by the code that originated the Navigate() request.
 241 Profile* GetSourceProfile(chrome::NavigateParams* params) {
 242   if (params->source_contents) {
 243     return Profile::FromBrowserContext(
 244         params->source_contents->GetBrowserContext());
 245   }
 246
 247   return params->initiating_profile;
 248 }
 249
 250 void LoadURLInContents(WebContents* target_contents,
 251                        const GURL& url,
 252                        chrome::NavigateParams* params) {
 253   NavigationController::LoadURLParams load_url_params(url);
 254   load_url_params.referrer = params->referrer;
 255   load_url_params.frame_tree_node_id = params->frame_tree_node_id;
 256   load_url_params.redirect_chain = params->redirect_chain;
 257   load_url_params.transition_type = params->transition;
 258   load_url_params.extra_headers = params->extra_headers;
 259   load_url_params.should_replace_current_entry =
 260       params->should_replace_current_entry;
 261
 262   if (params->transferred_global_request_id != GlobalRequestID()) {
 263     load_url_params.is_renderer_initiated = params->is_renderer_initiated;
 264     load_url_params.transferred_global_request_id =
 265         params->transferred_global_request_id;
 266   } else if (params->is_renderer_initiated) {
 267     load_url_params.is_renderer_initiated = true;
 268   }
 269
 270   // Only allows the browser-initiated navigation to use POST.
 271   if (params->uses_post && !params->is_renderer_initiated) {
 272     load_url_params.load_type =
 273         NavigationController::LOAD_TYPE_BROWSER_INITIATED_HTTP_POST;
 274     load_url_params.browser_initiated_post_data =
 275         params->browser_initiated_post_data;
 276   }
 277   target_contents->GetController().LoadURLWithParams(load_url_params);
 278 }
 279
 280 // This class makes sure the Browser object held in |params| is made visible
 281 // by the time it goes out of scope, provided |params| wants it to be shown.
 282 class ScopedBrowserShower {
 283  public:
 284   explicit ScopedBrowserShower(chrome::NavigateParams* params)
 285       : params_(params) {
 286   }
 287   ~ScopedBrowserShower() {
 288     if (params_->window_action == chrome::NavigateParams::SHOW_WINDOW_INACTIVE)
 289       params_->browser->window()->ShowInactive();
 290     else if (params_->window_action == chrome::NavigateParams::SHOW_WINDOW)
 291       params_->browser->window()->Show();
 292   }
 293  private:
 294   chrome::NavigateParams* params_;
 295   DISALLOW_COPY_AND_ASSIGN(ScopedBrowserShower);
 296 };
 297
 298 // This class manages the lifetime of a WebContents created by the
 299 // Navigate() function. When Navigate() creates a WebContents for a URL,
 300 // an instance of this class takes ownership of it via TakeOwnership() until the
 301 // WebContents is added to a tab strip at which time ownership is
 302 // relinquished via ReleaseOwnership(). If this object goes out of scope without
 303 // being added to a tab strip, the created WebContents is deleted to
 304 // avoid a leak and the params->target_contents field is set to NULL.
 305 class ScopedTargetContentsOwner {
 306  public:
 307   explicit ScopedTargetContentsOwner(chrome::NavigateParams* params)
 308       : params_(params) {
 309   }
 310   ~ScopedTargetContentsOwner() {
 311     if (target_contents_owner_.get())
 312       params_->target_contents = NULL;
 313   }
 314
 315   // Assumes ownership of |params_|' target_contents until ReleaseOwnership
 316   // is called.
 317   void TakeOwnership() {
 318     target_contents_owner_.reset(params_->target_contents);
 319   }
 320
 321   // Relinquishes ownership of |params_|' target_contents.
 322   WebContents* ReleaseOwnership() {
 323     return target_contents_owner_.release();
 324   }
 325
 326  private:
 327   chrome::NavigateParams* params_;
 328   scoped_ptr<WebContents> target_contents_owner_;
 329   DISALLOW_COPY_AND_ASSIGN(ScopedTargetContentsOwner);
 330 };
 331
 332 content::WebContents* CreateTargetContents(const chrome::NavigateParams& params,
 333                                            const GURL& url) {
 334   WebContents::CreateParams create_params(
 335       params.browser->profile(),
 336       tab_util::GetSiteInstanceForNewTab(params.browser->profile(), url));
 337   if (params.source_contents) {
 338     create_params.initial_size =
 339         params.source_contents->GetView()->GetContainerSize();
 340     if (params.should_set_opener)
 341       create_params.opener = params.source_contents;
 342   }
 343   if (params.disposition == NEW_BACKGROUND_TAB)
 344     create_params.initially_hidden = true;
 345
 346 #if defined(USE_AURA)
 347   if (params.browser->window() &&
 348       params.browser->window()->GetNativeWindow()) {
 349     create_params.context =
 350         params.browser->window()->GetNativeWindow();
 351   }
 352 #endif
 353
 354   WebContents* target_contents = WebContents::Create(create_params);
 355
 356   // New tabs can have WebUI URLs that will make calls back to arbitrary
 357   // tab helpers, so the entire set of tab helpers needs to be set up
 358   // immediately.
 359   BrowserNavigatorWebContentsAdoption::AttachTabHelpers(target_contents);
 360   extensions::TabHelper::FromWebContents(target_contents)->
 361       SetExtensionAppById(params.extension_app_id);
 362   return target_contents;
 363 }
 364
 365 // If a prerendered page exists for |url|, replace the page at
 366 // |params->target_contents| with it and update to point to the swapped-in
 367 // WebContents.
 368 bool SwapInPrerender(const GURL& url, chrome::NavigateParams* params) {
 369   Profile* profile =
 370       Profile::FromBrowserContext(params->target_contents->GetBrowserContext());
 371   InstantSearchPrerenderer* prerenderer =
 372       InstantSearchPrerenderer::GetForProfile(profile);
 373   if (prerenderer && prerenderer->UsePrerenderedPage(url, params))
 374     return true;
 375
 376   prerender::PrerenderManager* prerender_manager =
 377       prerender::PrerenderManagerFactory::GetForProfile(profile);
 378   return prerender_manager &&
 379       prerender_manager->MaybeUsePrerenderedPage(url, params);
 380 }
 381
 382 chrome::HostDesktopType GetHostDesktop(Browser* browser) {
 383   if (browser)
 384     return browser->host_desktop_type();
 385   return chrome::GetActiveDesktop();
 386 }
 387
 388 }  // namespace
 389
 390 namespace chrome {
 391
 392 NavigateParams::NavigateParams(Browser* a_browser,
 393                                const GURL& a_url,
 394                                content::PageTransition a_transition)
 395     : url(a_url),
 396       frame_tree_node_id(-1),
 397       uses_post(false),
 398       target_contents(NULL),
 399       source_contents(NULL),
 400       disposition(CURRENT_TAB),
 401       transition(a_transition),
 402       is_renderer_initiated(false),
 403       tabstrip_index(-1),
 404       tabstrip_add_types(TabStripModel::ADD_ACTIVE),
 405       window_action(NO_ACTION),
 406       user_gesture(true),
 407       path_behavior(RESPECT),
 408       ref_behavior(IGNORE_REF),
 409       browser(a_browser),
 410       initiating_profile(NULL),
 411       host_desktop_type(GetHostDesktop(a_browser)),
 412       should_replace_current_entry(false),
 413       should_set_opener(false) {
 414 }
 415
 416 NavigateParams::NavigateParams(Browser* a_browser,
 417                                WebContents* a_target_contents)
 418     : frame_tree_node_id(-1),
 419       uses_post(false),
 420       target_contents(a_target_contents),
 421       source_contents(NULL),
 422       disposition(CURRENT_TAB),
 423       transition(content::PAGE_TRANSITION_LINK),
 424       is_renderer_initiated(false),
 425       tabstrip_index(-1),
 426       tabstrip_add_types(TabStripModel::ADD_ACTIVE),
 427       window_action(NO_ACTION),
 428       user_gesture(true),
 429       path_behavior(RESPECT),
 430       ref_behavior(IGNORE_REF),
 431       browser(a_browser),
 432       initiating_profile(NULL),
 433       host_desktop_type(GetHostDesktop(a_browser)),
 434       should_replace_current_entry(false),
 435       should_set_opener(false) {
 436 }
 437
 438 NavigateParams::NavigateParams(Profile* a_profile,
 439                                const GURL& a_url,
 440                                content::PageTransition a_transition)
 441     : url(a_url),
 442       frame_tree_node_id(-1),
 443       uses_post(false),
 444       target_contents(NULL),
 445       source_contents(NULL),
 446       disposition(NEW_FOREGROUND_TAB),
 447       transition(a_transition),
 448       is_renderer_initiated(false),
 449       tabstrip_index(-1),
 450       tabstrip_add_types(TabStripModel::ADD_ACTIVE),
 451       window_action(SHOW_WINDOW),
 452       user_gesture(true),
 453       path_behavior(RESPECT),
 454       ref_behavior(IGNORE_REF),
 455       browser(NULL),
 456       initiating_profile(a_profile),
 457       host_desktop_type(chrome::GetActiveDesktop()),
 458       should_replace_current_entry(false),
 459       should_set_opener(false) {
 460 }
 461
 462 NavigateParams::~NavigateParams() {}
 463
 464 void FillNavigateParamsFromOpenURLParams(chrome::NavigateParams* nav_params,
 465                                          const content::OpenURLParams& params) {
 466   nav_params->referrer = params.referrer;
 467   nav_params->frame_tree_node_id = params.frame_tree_node_id;
 468   nav_params->redirect_chain = params.redirect_chain;
 469   nav_params->extra_headers = params.extra_headers;
 470   nav_params->disposition = params.disposition;
 471   nav_params->is_renderer_initiated = params.is_renderer_initiated;
 472   nav_params->transferred_global_request_id =
 473       params.transferred_global_request_id;
 474   nav_params->should_replace_current_entry =
 475       params.should_replace_current_entry;
 476   nav_params->uses_post = params.uses_post;
 477   nav_params->browser_initiated_post_data = params.browser_initiated_post_data;
 478 }
 479
 480 void Navigate(NavigateParams* params) {
 481   Browser* source_browser = params->browser;
 482   if (source_browser)
 483     params->initiating_profile = source_browser->profile();
 484   DCHECK(params->initiating_profile);
 485
 486   if (!AdjustNavigateParamsForURL(params))
 487     return;
 488
 489   const extensions::Extension* extension =
 490     extensions::ExtensionRegistry::Get(params->initiating_profile)->
 491         enabled_extensions().GetExtensionOrAppByURL(params->url);
 492   // Platform apps cannot navigate. Block the request.
 493   if (extension && extension->is_platform_app())
 494     params->url = GURL(chrome::kExtensionInvalidRequestURL);
 495
 496   // The browser window may want to adjust the disposition.
 497   if (params->disposition == NEW_POPUP &&
 498       source_browser &&
 499       source_browser->window()) {
 500     params->disposition =
 501         source_browser->window()->GetDispositionForPopupBounds(
 502             params->window_bounds);
 503   }
 504
 505   params->browser = GetBrowserForDisposition(params);
 506   if (!params->browser)
 507     return;
 508
 509 #if defined(USE_ASH)
 510   if (source_browser && source_browser != params->browser) {
 511     // When the newly created browser was spawned by a browser which visits
 512     // another user's desktop, it should be shown on the same desktop as the
 513     // originating one. (This is part of the desktop separation per profile).
 514     MultiUserWindowManager* manager = MultiUserWindowManager::GetInstance();
 515     // Some unit tests have no manager instantiated.
 516     if (manager) {
 517       aura::Window* src_window = source_browser->window()->GetNativeWindow();
 518       aura::Window* new_window = params->browser->window()->GetNativeWindow();
 519       const std::string& src_user =
 520           manager->GetUserPresentingWindow(src_window);
 521       if (src_user != manager->GetUserPresentingWindow(new_window)) {
 522         // Once the window gets presented, it should be shown on the same
 523         // desktop as the desktop of the creating browser. Note that this
 524         // command will not show the window if it wasn't shown yet by the
 525         // browser creation.
 526         manager->ShowWindowForUser(new_window, src_user);
 527       }
 528     }
 529   }
 530 #endif
 531
 532   // Navigate() must not return early after this point.
 533
 534   if (GetSourceProfile(params) != params->browser->profile()) {
 535     // A tab is being opened from a link from a different profile, we must reset
 536     // source information that may cause state to be shared.
 537     params->source_contents = NULL;
 538     params->referrer = content::Referrer();
 539   }
 540
 541   // Make sure the Browser is shown if params call for it.
 542   ScopedBrowserShower shower(params);
 543
 544   // Makes sure any WebContents created by this function is destroyed if
 545   // not properly added to a tab strip.
 546   ScopedTargetContentsOwner target_contents_owner(params);
 547
 548   // Some dispositions need coercion to base types.
 549   NormalizeDisposition(params);
 550
 551   // If a new window has been created, it needs to be shown.
 552   if (params->window_action == NavigateParams::NO_ACTION &&
 553       source_browser != params->browser &&
 554       params->browser->tab_strip_model()->empty()) {
 555     params->window_action = NavigateParams::SHOW_WINDOW;
 556   }
 557
 558   // If we create a popup window from a non user-gesture, don't activate it.
 559   if (params->window_action == NavigateParams::SHOW_WINDOW &&
 560       params->disposition == NEW_POPUP &&
 561       params->user_gesture == false) {
 562     params->window_action = NavigateParams::SHOW_WINDOW_INACTIVE;
 563   }
 564
 565   // Determine if the navigation was user initiated. If it was, we need to
 566   // inform the target WebContents, and we may need to update the UI.
 567   content::PageTransition base_transition =
 568       content::PageTransitionStripQualifier(params->transition);
 569   bool user_initiated =
 570       params->transition & content::PAGE_TRANSITION_FROM_ADDRESS_BAR ||
 571       base_transition == content::PAGE_TRANSITION_TYPED ||
 572       base_transition == content::PAGE_TRANSITION_AUTO_BOOKMARK ||
 573       base_transition == content::PAGE_TRANSITION_GENERATED ||
 574       base_transition == content::PAGE_TRANSITION_AUTO_TOPLEVEL ||
 575       base_transition == content::PAGE_TRANSITION_RELOAD ||
 576       base_transition == content::PAGE_TRANSITION_KEYWORD;
 577
 578   // Check if this is a singleton tab that already exists
 579   int singleton_index = chrome::GetIndexOfSingletonTab(params);
 580
 581   // Did we use a prerender?
 582   bool swapped_in_prerender = false;
 583
 584   // If no target WebContents was specified, we need to construct one if
 585   // we are supposed to target a new tab; unless it's a singleton that already
 586   // exists.
 587   if (!params->target_contents && singleton_index < 0) {
 588     GURL url;
 589     if (params->url.is_empty()) {
 590       url = params->browser->profile()->GetHomePage();
 591       params->transition = content::PageTransitionFromInt(
 592           params->transition | content::PAGE_TRANSITION_HOME_PAGE);
 593     } else {
 594       url = params->url;
 595     }
 596
 597     if (params->disposition != CURRENT_TAB) {
 598       params->target_contents = CreateTargetContents(*params, url);
 599
 600       // This function takes ownership of |params->target_contents| until it
 601       // is added to a TabStripModel.
 602       target_contents_owner.TakeOwnership();
 603     } else {
 604       // ... otherwise if we're loading in the current tab, the target is the
 605       // same as the source.
 606       DCHECK(params->source_contents);
 607       params->target_contents = params->source_contents;
 608       DCHECK(params->target_contents);
 609       // Prerender expects |params->target_contents| to be attached to a browser
 610       // window, so only call for CURRENT_TAB navigations. (Others are currently
 611       // unsupported because of session storage namespaces anyway.)
 612       // Notice that this includes middle-clicking, since middle clicking
 613       // translates into a chrome::Navigate call with no URL followed by a
 614       // CURRENT_TAB navigation.
 615       // TODO(tburkard): We can actually swap in in non-CURRENT_TAB cases, as
 616       // long as the WebContents we swap into is part of a TabStrip model.
 617       // Therefore, we should swap in regardless of CURRENT_TAB, and instead,
 618       // check in the swapin function whether the WebContents is not in a
 619       // TabStrip model, in which case we must not swap in.
 620       swapped_in_prerender = SwapInPrerender(url, params);
 621     }
 622
 623     if (user_initiated)
 624       params->target_contents->UserGestureDone();
 625
 626     if (!swapped_in_prerender) {
 627       // Try to handle non-navigational URLs that popup dialogs and such, these
 628       // should not actually navigate.
 629       if (!HandleNonNavigationAboutURL(url)) {
 630         // Perform the actual navigation, tracking whether it came from the
 631         // renderer.
 632
 633         LoadURLInContents(params->target_contents, url, params);
 634         // For prerender bookkeeping purposes, record that this pending navigate
 635         // originated from chrome::Navigate.
 636         content::NavigationEntry* entry =
 637             params->target_contents->GetController().GetPendingEntry();
 638         if (entry)
 639           entry->SetExtraData(prerender::kChromeNavigateExtraDataKey,
 640                               base::string16());
 641       }
 642     }
 643   } else {
 644     // |target_contents| was specified non-NULL, and so we assume it has already
 645     // been navigated appropriately. We need to do nothing more other than
 646     // add it to the appropriate tabstrip.
 647   }
 648
 649   // If the user navigated from the omnibox, and the selected tab is going to
 650   // lose focus, then make sure the focus for the source tab goes away from the
 651   // omnibox.
 652   if (params->source_contents &&
 653       (params->disposition == NEW_FOREGROUND_TAB ||
 654        params->disposition == NEW_WINDOW) &&
 655       (params->tabstrip_add_types & TabStripModel::ADD_INHERIT_OPENER))
 656     params->source_contents->GetView()->Focus();
 657
 658   if (params->source_contents == params->target_contents ||
 659       (swapped_in_prerender && params->disposition == CURRENT_TAB)) {
 660     // The navigation occurred in the source tab.
 661     params->browser->UpdateUIForNavigationInTab(params->target_contents,
 662                                                 params->transition,
 663                                                 user_initiated);
 664   } else if (singleton_index == -1) {
 665     // If some non-default value is set for the index, we should tell the
 666     // TabStripModel to respect it.
 667     if (params->tabstrip_index != -1)
 668       params->tabstrip_add_types |= TabStripModel::ADD_FORCE_INDEX;
 669
 670     // The navigation should insert a new tab into the target Browser.
 671     params->browser->tab_strip_model()->AddWebContents(
 672         params->target_contents,
 673         params->tabstrip_index,
 674         params->transition,
 675         params->tabstrip_add_types);
 676     // Now that the |params->target_contents| is safely owned by the target
 677     // Browser's TabStripModel, we can release ownership.
 678     target_contents_owner.ReleaseOwnership();
 679   }
 680
 681   if (singleton_index >= 0) {
 682     WebContents* target =
 683         params->browser->tab_strip_model()->GetWebContentsAt(singleton_index);
 684
 685     if (target->IsCrashed()) {
 686       target->GetController().Reload(true);
 687     } else if (params->path_behavior == NavigateParams::IGNORE_AND_NAVIGATE &&
 688         target->GetURL() != params->url) {
 689       LoadURLInContents(target, params->url, params);
 690       // For prerender bookkeeping purposes, record that this pending navigate
 691       // originated from chrome::Navigate.
 692       content::NavigationEntry* entry =
 693           target->GetController().GetPendingEntry();
 694       if (entry)
 695         entry->SetExtraData(prerender::kChromeNavigateExtraDataKey,
 696                             base::string16());
 697     }
 698
 699     // If the singleton tab isn't already selected, select it.
 700     if (params->source_contents != params->target_contents) {
 701       params->browser->tab_strip_model()->ActivateTabAt(singleton_index,
 702                                                         user_initiated);
 703     }
 704   }
 705
 706   if (params->disposition != CURRENT_TAB) {
 707     content::NotificationService::current()->Notify(
 708         chrome::NOTIFICATION_TAB_ADDED,
 709         content::Source<content::WebContentsDelegate>(params->browser),
 710         content::Details<WebContents>(params->target_contents));
 711   }
 712 }
 713
 714 bool IsURLAllowedInIncognito(const GURL& url,
 715                              content::BrowserContext* browser_context) {
 716   if (url.scheme() == content::kViewSourceScheme) {
 717     // A view-source URL is allowed in incognito mode only if the URL itself
 718     // is allowed in incognito mode. Remove the "view-source:" from the start
 719     // of the URL and validate the rest.
 720     std::string stripped_spec = url.spec();
 721     DCHECK_GT(stripped_spec.size(), strlen(content::kViewSourceScheme));
 722     stripped_spec.erase(0, strlen(content::kViewSourceScheme) + 1);
 723     GURL stripped_url(stripped_spec);
 724     return stripped_url.is_valid() &&
 725         IsURLAllowedInIncognito(stripped_url, browser_context);
 726   }
 727   // Most URLs are allowed in incognito; the following are exceptions.
 728   // chrome://extensions is on the list because it redirects to
 729   // chrome://settings.
 730   if (url.scheme() == content::kChromeUIScheme &&
 731       (url.host() == chrome::kChromeUISettingsHost ||
 732        url.host() == chrome::kChromeUISettingsFrameHost ||
 733        url.host() == chrome::kChromeUIExtensionsHost ||
 734        url.host() == chrome::kChromeUIBookmarksHost ||
 735 #if !defined(OS_CHROMEOS)
 736        url.host() == chrome::kChromeUIChromeSigninHost ||
 737 #endif
 738        url.host() == chrome::kChromeUIUberHost ||
 739        url.host() == chrome::kChromeUIThumbnailHost ||
 740        url.host() == chrome::kChromeUIThumbnailHost2 ||
 741        url.host() == chrome::kChromeUIThumbnailListHost ||
 742        url.host() == chrome::kChromeUISuggestionsHost)) {
 743     return false;
 744   }
 745
 746   if (url.scheme() == chrome::kChromeSearchScheme &&
 747       (url.host() == chrome::kChromeUIThumbnailHost ||
 748        url.host() == chrome::kChromeUIThumbnailHost2 ||
 749        url.host() == chrome::kChromeUIThumbnailListHost ||
 750        url.host() == chrome::kChromeUISuggestionsHost)) {
 751     return false;
 752   }
 753
 754   GURL rewritten_url = url;
 755   bool reverse_on_redirect = false;
 756   content::BrowserURLHandler::GetInstance()->RewriteURLIfNecessary(
 757       &rewritten_url, browser_context, &reverse_on_redirect);
 758
 759   // Some URLs are mapped to uber subpages. Do not allow them in incognito.
 760   return !(rewritten_url.scheme() == content::kChromeUIScheme &&
 761            rewritten_url.host() == chrome::kChromeUIUberHost);
 762 }
 763
 764 }  // namespace chrome