chrome/browser/prerender/prerender_contents.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/prerender/prerender_contents.h"
   6
   7 #include <algorithm>
   8 #include <functional>
   9 #include <utility>
  10
  11 #include "base/bind.h"
  12 #include "base/strings/utf_string_conversions.h"
  13 #include "chrome/browser/chrome_notification_types.h"
  14 #include "chrome/browser/history/history_tab_helper.h"
  15 #include "chrome/browser/prerender/prerender_field_trial.h"
  16 #include "chrome/browser/prerender/prerender_final_status.h"
  17 #include "chrome/browser/prerender/prerender_handle.h"
  18 #include "chrome/browser/prerender/prerender_manager.h"
  19 #include "chrome/browser/prerender/prerender_manager_factory.h"
  20 #include "chrome/browser/prerender/prerender_resource_throttle.h"
  21 #include "chrome/browser/profiles/profile.h"
  22 #include "chrome/browser/ui/browser.h"
  23 #include "chrome/browser/ui/tab_helpers.h"
  24 #include "chrome/browser/ui/web_contents_sizer.h"
  25 #include "chrome/common/prerender_messages.h"
  26 #include "chrome/common/render_messages.h"
  27 #include "chrome/common/url_constants.h"
  28 #include "components/history/core/browser/history_types.h"
  29 #include "content/public/browser/browser_child_process_host.h"
  30 #include "content/public/browser/browser_thread.h"
  31 #include "content/public/browser/notification_service.h"
  32 #include "content/public/browser/render_frame_host.h"
  33 #include "content/public/browser/render_process_host.h"
  34 #include "content/public/browser/render_view_host.h"
  35 #include "content/public/browser/resource_request_details.h"
  36 #include "content/public/browser/session_storage_namespace.h"
  37 #include "content/public/browser/web_contents.h"
  38 #include "content/public/browser/web_contents_delegate.h"
  39 #include "content/public/common/frame_navigate_params.h"
  40 #include "ui/base/page_transition_types.h"
  41 #include "ui/gfx/geometry/rect.h"
  42
  43 using content::BrowserThread;
  44 using content::DownloadItem;
  45 using content::OpenURLParams;
  46 using content::RenderViewHost;
  47 using content::ResourceRedirectDetails;
  48 using content::ResourceType;
  49 using content::SessionStorageNamespace;
  50 using content::WebContents;
  51
  52 namespace prerender {
  53
  54 namespace {
  55
  56 void ResumeThrottles(
  57     std::vector<base::WeakPtr<PrerenderResourceThrottle> > throttles) {
  58   for (size_t i = 0; i < throttles.size(); i++) {
  59     if (throttles[i])
  60       throttles[i]->Resume();
  61   }
  62 }
  63
  64 }  // namespace
  65
  66 class PrerenderContentsFactoryImpl : public PrerenderContents::Factory {
  67  public:
  68   PrerenderContents* CreatePrerenderContents(
  69       PrerenderManager* prerender_manager,
  70       Profile* profile,
  71       const GURL& url,
  72       const content::Referrer& referrer,
  73       Origin origin) override {
  74     return new PrerenderContents(prerender_manager, profile, url, referrer,
  75                                  origin);
  76   }
  77 };
  78
  79 // WebContentsDelegateImpl -----------------------------------------------------
  80
  81 class PrerenderContents::WebContentsDelegateImpl
  82     : public content::WebContentsDelegate {
  83  public:
  84   explicit WebContentsDelegateImpl(PrerenderContents* prerender_contents)
  85       : prerender_contents_(prerender_contents) {
  86   }
  87
  88   // content::WebContentsDelegate implementation:
  89   WebContents* OpenURLFromTab(WebContents* source,
  90                               const OpenURLParams& params) override {
  91     // |OpenURLFromTab| is typically called when a frame performs a navigation
  92     // that requires the browser to perform the transition instead of WebKit.
  93     // Examples include prerendering a site that redirects to an app URL, or if
  94     // --site-per-process is specified and the prerendered frame redirects to a
  95     // different origin.
  96     // TODO(cbentzel): Consider supporting this for CURRENT_TAB dispositions, if
  97     // it is a common case during prerenders.
  98     prerender_contents_->Destroy(FINAL_STATUS_OPEN_URL);
  99     return NULL;
 100   }
 101
 102   void CloseContents(content::WebContents* contents) override {
 103     prerender_contents_->Destroy(FINAL_STATUS_CLOSED);
 104   }
 105
 106   void CanDownload(const GURL& url,
 107                    const std::string& request_method,
 108                    const base::Callback<void(bool)>& callback) override {
 109     prerender_contents_->Destroy(FINAL_STATUS_DOWNLOAD);
 110     // Cancel the download.
 111     callback.Run(false);
 112   }
 113
 114   bool ShouldCreateWebContents(
 115       WebContents* web_contents,
 116       int route_id,
 117       int main_frame_route_id,
 118       WindowContainerType window_container_type,
 119       const base::string16& frame_name,
 120       const GURL& target_url,
 121       const std::string& partition_id,
 122       SessionStorageNamespace* session_storage_namespace) override {
 123     // Since we don't want to permit child windows that would have a
 124     // window.opener property, terminate prerendering.
 125     prerender_contents_->Destroy(FINAL_STATUS_CREATE_NEW_WINDOW);
 126     // Cancel the popup.
 127     return false;
 128   }
 129
 130   bool OnGoToEntryOffset(int offset) override {
 131     // This isn't allowed because the history merge operation
 132     // does not work if there are renderer issued challenges.
 133     // TODO(cbentzel): Cancel in this case? May not need to do
 134     // since render-issued offset navigations are not guaranteed,
 135     // but indicates that the page cares about the history.
 136     return false;
 137   }
 138
 139   bool ShouldSuppressDialogs(WebContents* source) override {
 140     // We still want to show the user the message when they navigate to this
 141     // page, so cancel this prerender.
 142     prerender_contents_->Destroy(FINAL_STATUS_JAVASCRIPT_ALERT);
 143     // Always suppress JavaScript messages if they're triggered by a page being
 144     // prerendered.
 145     return true;
 146   }
 147
 148   void RegisterProtocolHandler(WebContents* web_contents,
 149                                const std::string& protocol,
 150                                const GURL& url,
 151                                bool user_gesture) override {
 152     // TODO(mmenke): Consider supporting this if it is a common case during
 153     // prerenders.
 154     prerender_contents_->Destroy(FINAL_STATUS_REGISTER_PROTOCOL_HANDLER);
 155   }
 156
 157   gfx::Size GetSizeForNewRenderView(WebContents* web_contents) const override {
 158     // Have to set the size of the RenderView on initialization to be sure it is
 159     // set before the RenderView is hidden on all platforms (esp. Android).
 160     return prerender_contents_->size_;
 161   }
 162
 163  private:
 164   PrerenderContents* prerender_contents_;
 165 };
 166
 167 void PrerenderContents::Observer::OnPrerenderStopLoading(
 168     PrerenderContents* contents) {
 169 }
 170
 171 void PrerenderContents::Observer::OnPrerenderDomContentLoaded(
 172     PrerenderContents* contents) {
 173 }
 174
 175 void PrerenderContents::Observer::OnPrerenderCreatedMatchCompleteReplacement(
 176     PrerenderContents* contents, PrerenderContents* replacement) {
 177 }
 178
 179 PrerenderContents::Observer::Observer() {
 180 }
 181
 182 PrerenderContents::Observer::~Observer() {
 183 }
 184
 185 PrerenderContents::PrerenderContents(
 186     PrerenderManager* prerender_manager,
 187     Profile* profile,
 188     const GURL& url,
 189     const content::Referrer& referrer,
 190     Origin origin)
 191     : prerendering_has_started_(false),
 192       session_storage_namespace_id_(-1),
 193       prerender_manager_(prerender_manager),
 194       prerender_url_(url),
 195       referrer_(referrer),
 196       profile_(profile),
 197       page_id_(0),
 198       has_stopped_loading_(false),
 199       has_finished_loading_(false),
 200       final_status_(FINAL_STATUS_MAX),
 201       match_complete_status_(MATCH_COMPLETE_DEFAULT),
 202       prerendering_has_been_cancelled_(false),
 203       child_id_(-1),
 204       route_id_(-1),
 205       origin_(origin),
 206       network_bytes_(0) {
 207   DCHECK(prerender_manager != NULL);
 208 }
 209
 210 PrerenderContents* PrerenderContents::CreateMatchCompleteReplacement() {
 211   PrerenderContents* new_contents = prerender_manager_->CreatePrerenderContents(
 212       prerender_url(), referrer(), origin());
 213
 214   new_contents->load_start_time_ = load_start_time_;
 215   new_contents->session_storage_namespace_id_ = session_storage_namespace_id_;
 216   new_contents->set_match_complete_status(
 217       PrerenderContents::MATCH_COMPLETE_REPLACEMENT_PENDING);
 218
 219   const bool did_init = new_contents->Init();
 220   DCHECK(did_init);
 221   DCHECK_EQ(alias_urls_.front(), new_contents->alias_urls_.front());
 222   DCHECK_EQ(1u, new_contents->alias_urls_.size());
 223   new_contents->alias_urls_ = alias_urls_;
 224   // Erase all but the first alias URL; the replacement has adopted the
 225   // remainder without increasing the renderer-side reference count.
 226   alias_urls_.resize(1);
 227   new_contents->set_match_complete_status(
 228       PrerenderContents::MATCH_COMPLETE_REPLACEMENT);
 229   NotifyPrerenderCreatedMatchCompleteReplacement(new_contents);
 230   return new_contents;
 231 }
 232
 233 bool PrerenderContents::Init() {
 234   return AddAliasURL(prerender_url_);
 235 }
 236
 237 // static
 238 PrerenderContents::Factory* PrerenderContents::CreateFactory() {
 239   return new PrerenderContentsFactoryImpl();
 240 }
 241
 242 // static
 243 PrerenderContents* PrerenderContents::FromWebContents(
 244     content::WebContents* web_contents) {
 245   if (!web_contents)
 246     return NULL;
 247   PrerenderManager* prerender_manager = PrerenderManagerFactory::GetForProfile(
 248       Profile::FromBrowserContext(web_contents->GetBrowserContext()));
 249   if (!prerender_manager)
 250     return NULL;
 251   return prerender_manager->GetPrerenderContents(web_contents);
 252 }
 253
 254 void PrerenderContents::StartPrerendering(
 255     const gfx::Size& size,
 256     SessionStorageNamespace* session_storage_namespace) {
 257   DCHECK(profile_ != NULL);
 258   DCHECK(!size.IsEmpty());
 259   DCHECK(!prerendering_has_started_);
 260   DCHECK(prerender_contents_.get() == NULL);
 261   DCHECK(size_.IsEmpty());
 262   DCHECK_EQ(1U, alias_urls_.size());
 263
 264   session_storage_namespace_id_ = session_storage_namespace->id();
 265   size_ = size;
 266
 267   DCHECK(load_start_time_.is_null());
 268   load_start_time_ = base::TimeTicks::Now();
 269
 270   // Everything after this point sets up the WebContents object and associated
 271   // RenderView for the prerender page. Don't do this for members of the
 272   // control group.
 273   if (prerender_manager_->IsControlGroup())
 274     return;
 275
 276   prerendering_has_started_ = true;
 277
 278   prerender_contents_.reset(CreateWebContents(session_storage_namespace));
 279   TabHelpers::AttachTabHelpers(prerender_contents_.get());
 280   content::WebContentsObserver::Observe(prerender_contents_.get());
 281
 282   web_contents_delegate_.reset(new WebContentsDelegateImpl(this));
 283   prerender_contents_.get()->SetDelegate(web_contents_delegate_.get());
 284   // Set the size of the prerender WebContents.
 285   ResizeWebContents(prerender_contents_.get(), size_);
 286
 287   // TODO(davidben): This logic assumes each prerender has at most one
 288   // route. https://crbug.com/440544
 289   child_id_ = GetRenderViewHost()->GetProcess()->GetID();
 290   route_id_ = GetRenderViewHost()->GetRoutingID();
 291
 292   // TODO(davidben): This logic assumes each prerender has at most one
 293   // process. https://crbug.com/440544
 294   prerender_manager()->AddPrerenderProcessHost(
 295       GetRenderViewHost()->GetProcess());
 296
 297   NotifyPrerenderStart();
 298
 299   // Close ourselves when the application is shutting down.
 300   notification_registrar_.Add(this, chrome::NOTIFICATION_APP_TERMINATING,
 301                               content::NotificationService::AllSources());
 302
 303   // Register to inform new RenderViews that we're prerendering.
 304   notification_registrar_.Add(
 305       this, content::NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED,
 306       content::Source<WebContents>(prerender_contents_.get()));
 307
 308   // Transfer over the user agent override.
 309   prerender_contents_.get()->SetUserAgentOverride(
 310       prerender_manager_->config().user_agent_override);
 311
 312   content::NavigationController::LoadURLParams load_url_params(
 313       prerender_url_);
 314   load_url_params.referrer = referrer_;
 315   load_url_params.transition_type = ui::PAGE_TRANSITION_LINK;
 316   if (origin_ == ORIGIN_OMNIBOX) {
 317     load_url_params.transition_type = ui::PageTransitionFromInt(
 318         ui::PAGE_TRANSITION_TYPED |
 319         ui::PAGE_TRANSITION_FROM_ADDRESS_BAR);
 320   } else if (origin_ == ORIGIN_INSTANT) {
 321     load_url_params.transition_type = ui::PageTransitionFromInt(
 322         ui::PAGE_TRANSITION_GENERATED |
 323         ui::PAGE_TRANSITION_FROM_ADDRESS_BAR);
 324   }
 325   load_url_params.override_user_agent =
 326       prerender_manager_->config().is_overriding_user_agent ?
 327       content::NavigationController::UA_OVERRIDE_TRUE :
 328       content::NavigationController::UA_OVERRIDE_FALSE;
 329   prerender_contents_.get()->GetController().LoadURLWithParams(load_url_params);
 330 }
 331
 332 bool PrerenderContents::GetChildId(int* child_id) const {
 333   CHECK(child_id);
 334   DCHECK_GE(child_id_, -1);
 335   *child_id = child_id_;
 336   return child_id_ != -1;
 337 }
 338
 339 bool PrerenderContents::GetRouteId(int* route_id) const {
 340   CHECK(route_id);
 341   DCHECK_GE(route_id_, -1);
 342   *route_id = route_id_;
 343   return route_id_ != -1;
 344 }
 345
 346 void PrerenderContents::SetFinalStatus(FinalStatus final_status) {
 347   DCHECK_GE(final_status, FINAL_STATUS_USED);
 348   DCHECK_LT(final_status, FINAL_STATUS_MAX);
 349
 350   DCHECK_EQ(FINAL_STATUS_MAX, final_status_);
 351
 352   final_status_ = final_status;
 353 }
 354
 355 PrerenderContents::~PrerenderContents() {
 356   DCHECK_NE(FINAL_STATUS_MAX, final_status());
 357   DCHECK(
 358       prerendering_has_been_cancelled() || final_status() == FINAL_STATUS_USED);
 359   DCHECK_NE(ORIGIN_MAX, origin());
 360
 361   prerender_manager_->RecordFinalStatusWithMatchCompleteStatus(
 362       origin(), match_complete_status(), final_status());
 363
 364   bool used = final_status() == FINAL_STATUS_USED ||
 365               final_status() == FINAL_STATUS_WOULD_HAVE_BEEN_USED;
 366   prerender_manager_->RecordNetworkBytes(origin(), used, network_bytes_);
 367
 368   // Broadcast the removal of aliases.
 369   for (content::RenderProcessHost::iterator host_iterator =
 370            content::RenderProcessHost::AllHostsIterator();
 371        !host_iterator.IsAtEnd();
 372        host_iterator.Advance()) {
 373     content::RenderProcessHost* host = host_iterator.GetCurrentValue();
 374     host->Send(new PrerenderMsg_OnPrerenderRemoveAliases(alias_urls_));
 375   }
 376
 377   // If we still have a WebContents, clean up anything we need to and then
 378   // destroy it.
 379   if (prerender_contents_.get())
 380     delete ReleasePrerenderContents();
 381 }
 382
 383 void PrerenderContents::AddObserver(Observer* observer) {
 384   DCHECK_EQ(FINAL_STATUS_MAX, final_status_);
 385   observer_list_.AddObserver(observer);
 386 }
 387
 388 void PrerenderContents::RemoveObserver(Observer* observer) {
 389   observer_list_.RemoveObserver(observer);
 390 }
 391
 392 void PrerenderContents::Observe(int type,
 393                                 const content::NotificationSource& source,
 394                                 const content::NotificationDetails& details) {
 395   switch (type) {
 396     // TODO(davidben): Try to remove this in favor of relying on
 397     // FINAL_STATUS_PROFILE_DESTROYED.
 398     case chrome::NOTIFICATION_APP_TERMINATING:
 399       Destroy(FINAL_STATUS_APP_TERMINATING);
 400       return;
 401
 402     case content::NOTIFICATION_WEB_CONTENTS_RENDER_VIEW_HOST_CREATED: {
 403       if (prerender_contents_.get()) {
 404         DCHECK_EQ(content::Source<WebContents>(source).ptr(),
 405                   prerender_contents_.get());
 406
 407         content::Details<RenderViewHost> new_render_view_host(details);
 408         OnRenderViewHostCreated(new_render_view_host.ptr());
 409
 410         // Make sure the size of the RenderViewHost has been passed to the new
 411         // RenderView.  Otherwise, the size may not be sent until the
 412         // RenderViewReady event makes it from the render process to the UI
 413         // thread of the browser process.  When the RenderView receives its
 414         // size, is also sets itself to be visible, which would then break the
 415         // visibility API.
 416         new_render_view_host->WasResized();
 417         prerender_contents_->WasHidden();
 418       }
 419       break;
 420     }
 421
 422     default:
 423       NOTREACHED() << "Unexpected notification sent.";
 424       break;
 425   }
 426 }
 427
 428 void PrerenderContents::OnRenderViewHostCreated(
 429     RenderViewHost* new_render_view_host) {
 430 }
 431
 432 WebContents* PrerenderContents::CreateWebContents(
 433     SessionStorageNamespace* session_storage_namespace) {
 434   // TODO(ajwong): Remove the temporary map once prerendering is aware of
 435   // multiple session storage namespaces per tab.
 436   content::SessionStorageNamespaceMap session_storage_namespace_map;
 437   session_storage_namespace_map[std::string()] = session_storage_namespace;
 438   return WebContents::CreateWithSessionStorage(
 439       WebContents::CreateParams(profile_), session_storage_namespace_map);
 440 }
 441
 442 void PrerenderContents::NotifyPrerenderStart() {
 443   DCHECK_EQ(FINAL_STATUS_MAX, final_status_);
 444   FOR_EACH_OBSERVER(Observer, observer_list_, OnPrerenderStart(this));
 445 }
 446
 447 void PrerenderContents::NotifyPrerenderStopLoading() {
 448   FOR_EACH_OBSERVER(Observer, observer_list_, OnPrerenderStopLoading(this));
 449 }
 450
 451 void PrerenderContents::NotifyPrerenderDomContentLoaded() {
 452   FOR_EACH_OBSERVER(Observer, observer_list_,
 453                     OnPrerenderDomContentLoaded(this));
 454 }
 455
 456 void PrerenderContents::NotifyPrerenderStop() {
 457   DCHECK_NE(FINAL_STATUS_MAX, final_status_);
 458   FOR_EACH_OBSERVER(Observer, observer_list_, OnPrerenderStop(this));
 459   observer_list_.Clear();
 460 }
 461
 462 void PrerenderContents::NotifyPrerenderCreatedMatchCompleteReplacement(
 463     PrerenderContents* replacement) {
 464   FOR_EACH_OBSERVER(Observer, observer_list_,
 465                     OnPrerenderCreatedMatchCompleteReplacement(this,
 466                                                                replacement));
 467 }
 468
 469 bool PrerenderContents::OnMessageReceived(const IPC::Message& message) {
 470   bool handled = true;
 471   // The following messages we do want to consume.
 472   IPC_BEGIN_MESSAGE_MAP(PrerenderContents, message)
 473     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_CancelPrerenderForPrinting,
 474                         OnCancelPrerenderForPrinting)
 475     IPC_MESSAGE_UNHANDLED(handled = false)
 476   IPC_END_MESSAGE_MAP()
 477
 478   return handled;
 479 }
 480
 481 bool PrerenderContents::CheckURL(const GURL& url) {
 482   if (!url.SchemeIsHTTPOrHTTPS()) {
 483     DCHECK_NE(MATCH_COMPLETE_REPLACEMENT_PENDING, match_complete_status_);
 484     Destroy(FINAL_STATUS_UNSUPPORTED_SCHEME);
 485     return false;
 486   }
 487   if (match_complete_status_ != MATCH_COMPLETE_REPLACEMENT_PENDING &&
 488       prerender_manager_->HasRecentlyBeenNavigatedTo(origin(), url)) {
 489     Destroy(FINAL_STATUS_RECENTLY_VISITED);
 490     return false;
 491   }
 492   return true;
 493 }
 494
 495 bool PrerenderContents::AddAliasURL(const GURL& url) {
 496   if (!CheckURL(url))
 497     return false;
 498
 499   alias_urls_.push_back(url);
 500
 501   for (content::RenderProcessHost::iterator host_iterator =
 502            content::RenderProcessHost::AllHostsIterator();
 503        !host_iterator.IsAtEnd();
 504        host_iterator.Advance()) {
 505     content::RenderProcessHost* host = host_iterator.GetCurrentValue();
 506     host->Send(new PrerenderMsg_OnPrerenderAddAlias(url));
 507   }
 508
 509   return true;
 510 }
 511
 512 bool PrerenderContents::Matches(
 513     const GURL& url,
 514     const SessionStorageNamespace* session_storage_namespace) const {
 515   // TODO(davidben): Remove any consumers that pass in a NULL
 516   // session_storage_namespace and only test with matches.
 517   if (session_storage_namespace &&
 518       session_storage_namespace_id_ != session_storage_namespace->id()) {
 519     return false;
 520   }
 521   return std::count_if(alias_urls_.begin(), alias_urls_.end(),
 522                        std::bind2nd(std::equal_to<GURL>(), url)) != 0;
 523 }
 524
 525 void PrerenderContents::RenderProcessGone(base::TerminationStatus status) {
 526   Destroy(FINAL_STATUS_RENDERER_CRASHED);
 527 }
 528
 529 void PrerenderContents::RenderFrameCreated(
 530     content::RenderFrameHost* render_frame_host) {
 531   // When a new RenderFrame is created for a prerendering WebContents, tell the
 532   // new RenderFrame it's being used for prerendering before any navigations
 533   // occur.  Note that this is always triggered before the first navigation, so
 534   // there's no need to send the message just after the WebContents is created.
 535   render_frame_host->Send(new PrerenderMsg_SetIsPrerendering(
 536       render_frame_host->GetRoutingID(), true));
 537 }
 538
 539 void PrerenderContents::DidStopLoading() {
 540   has_stopped_loading_ = true;
 541   NotifyPrerenderStopLoading();
 542 }
 543
 544 void PrerenderContents::DocumentLoadedInFrame(
 545     content::RenderFrameHost* render_frame_host) {
 546   if (!render_frame_host->GetParent())
 547     NotifyPrerenderDomContentLoaded();
 548 }
 549
 550 void PrerenderContents::DidStartProvisionalLoadForFrame(
 551     content::RenderFrameHost* render_frame_host,
 552     const GURL& validated_url,
 553     bool is_error_page,
 554     bool is_iframe_srcdoc) {
 555   if (!render_frame_host->GetParent()) {
 556     if (!CheckURL(validated_url))
 557       return;
 558
 559     // Usually, this event fires if the user clicks or enters a new URL.
 560     // Neither of these can happen in the case of an invisible prerender.
 561     // So the cause is: Some JavaScript caused a new URL to be loaded.  In that
 562     // case, the spinner would start again in the browser, so we must reset
 563     // has_stopped_loading_ so that the spinner won't be stopped.
 564     has_stopped_loading_ = false;
 565     has_finished_loading_ = false;
 566   }
 567 }
 568
 569 void PrerenderContents::DidFinishLoad(
 570     content::RenderFrameHost* render_frame_host,
 571     const GURL& validated_url) {
 572   if (!render_frame_host->GetParent())
 573     has_finished_loading_ = true;
 574 }
 575
 576 void PrerenderContents::DidNavigateMainFrame(
 577     const content::LoadCommittedDetails& details,
 578     const content::FrameNavigateParams& params) {
 579   // If the prerender made a second navigation entry, abort the prerender. This
 580   // avoids having to correctly implement a complex history merging case (this
 581   // interacts with location.replace) and correctly synchronize with the
 582   // renderer. The final status may be monitored to see we need to revisit this
 583   // decision. This does not affect client redirects as those do not push new
 584   // history entries. (Calls to location.replace, navigations before onload, and
 585   // <meta http-equiv=refresh> with timeouts under 1 second do not create
 586   // entries in Blink.)
 587   if (prerender_contents_->GetController().GetEntryCount() > 1) {
 588     Destroy(FINAL_STATUS_NEW_NAVIGATION_ENTRY);
 589     return;
 590   }
 591
 592   // Add each redirect as an alias. |params.url| is included in
 593   // |params.redirects|.
 594   //
 595   // TODO(davidben): We do not correctly patch up history for renderer-initated
 596   // navigations which add history entries. http://crbug.com/305660.
 597   for (size_t i = 0; i < params.redirects.size(); i++) {
 598     if (!AddAliasURL(params.redirects[i]))
 599       return;
 600   }
 601 }
 602
 603 void PrerenderContents::DidGetRedirectForResourceRequest(
 604     content::RenderFrameHost* render_frame_host,
 605     const content::ResourceRedirectDetails& details) {
 606   // DidGetRedirectForResourceRequest can come for any resource on a page.  If
 607   // it's a redirect on the top-level resource, the name needs to be remembered
 608   // for future matching, and if it redirects to an https resource, it needs to
 609   // be canceled. If a subresource is redirected, nothing changes.
 610   if (details.resource_type != content::RESOURCE_TYPE_MAIN_FRAME)
 611     return;
 612   CheckURL(details.new_url);
 613 }
 614
 615 void PrerenderContents::Destroy(FinalStatus final_status) {
 616   DCHECK_NE(final_status, FINAL_STATUS_USED);
 617
 618   if (prerendering_has_been_cancelled_)
 619     return;
 620
 621   SetFinalStatus(final_status);
 622
 623   prerendering_has_been_cancelled_ = true;
 624   prerender_manager_->AddToHistory(this);
 625   prerender_manager_->MoveEntryToPendingDelete(this, final_status);
 626
 627   // Note that if this PrerenderContents was made into a MatchComplete
 628   // replacement by MoveEntryToPendingDelete, NotifyPrerenderStop will
 629   // not reach the PrerenderHandle. Rather
 630   // OnPrerenderCreatedMatchCompleteReplacement will propogate that
 631   // information to the referer.
 632   if (!prerender_manager_->IsControlGroup() &&
 633       (prerendering_has_started() ||
 634        match_complete_status() == MATCH_COMPLETE_REPLACEMENT)) {
 635     NotifyPrerenderStop();
 636   }
 637 }
 638
 639 base::ProcessMetrics* PrerenderContents::MaybeGetProcessMetrics() {
 640   if (process_metrics_.get() == NULL) {
 641     // If a PrenderContents hasn't started prerending, don't be fully formed.
 642     if (!GetRenderViewHost() || !GetRenderViewHost()->GetProcess())
 643       return NULL;
 644     base::ProcessHandle handle = GetRenderViewHost()->GetProcess()->GetHandle();
 645     if (handle == base::kNullProcessHandle)
 646       return NULL;
 647 #if !defined(OS_MACOSX)
 648     process_metrics_.reset(base::ProcessMetrics::CreateProcessMetrics(handle));
 649 #else
 650     process_metrics_.reset(base::ProcessMetrics::CreateProcessMetrics(
 651         handle,
 652         content::BrowserChildProcessHost::GetPortProvider()));
 653 #endif
 654   }
 655
 656   return process_metrics_.get();
 657 }
 658
 659 void PrerenderContents::DestroyWhenUsingTooManyResources() {
 660   base::ProcessMetrics* metrics = MaybeGetProcessMetrics();
 661   if (metrics == NULL)
 662     return;
 663
 664   size_t private_bytes, shared_bytes;
 665   if (metrics->GetMemoryBytes(&private_bytes, &shared_bytes) &&
 666       private_bytes > prerender_manager_->config().max_bytes) {
 667     Destroy(FINAL_STATUS_MEMORY_LIMIT_EXCEEDED);
 668   }
 669 }
 670
 671 WebContents* PrerenderContents::ReleasePrerenderContents() {
 672   prerender_contents_->SetDelegate(NULL);
 673   content::WebContentsObserver::Observe(NULL);
 674   return prerender_contents_.release();
 675 }
 676
 677 RenderViewHost* PrerenderContents::GetRenderViewHostMutable() {
 678   return const_cast<RenderViewHost*>(GetRenderViewHost());
 679 }
 680
 681 const RenderViewHost* PrerenderContents::GetRenderViewHost() const {
 682   if (!prerender_contents_.get())
 683     return NULL;
 684   return prerender_contents_->GetRenderViewHost();
 685 }
 686
 687 void PrerenderContents::DidNavigate(
 688     const history::HistoryAddPageArgs& add_page_args) {
 689   add_page_vector_.push_back(add_page_args);
 690 }
 691
 692 void PrerenderContents::CommitHistory(WebContents* tab) {
 693   HistoryTabHelper* history_tab_helper = HistoryTabHelper::FromWebContents(tab);
 694   for (size_t i = 0; i < add_page_vector_.size(); ++i)
 695     history_tab_helper->UpdateHistoryForNavigation(add_page_vector_[i]);
 696 }
 697
 698 base::Value* PrerenderContents::GetAsValue() const {
 699   if (!prerender_contents_.get())
 700     return NULL;
 701   base::DictionaryValue* dict_value = new base::DictionaryValue();
 702   dict_value->SetString("url", prerender_url_.spec());
 703   base::TimeTicks current_time = base::TimeTicks::Now();
 704   base::TimeDelta duration = current_time - load_start_time_;
 705   dict_value->SetInteger("duration", duration.InSeconds());
 706   dict_value->SetBoolean("is_loaded", prerender_contents_ &&
 707                                       !prerender_contents_->IsLoading());
 708   return dict_value;
 709 }
 710
 711 bool PrerenderContents::IsCrossSiteNavigationPending() const {
 712   if (!prerender_contents_)
 713     return false;
 714   return (prerender_contents_->GetSiteInstance() !=
 715           prerender_contents_->GetPendingSiteInstance());
 716 }
 717
 718 void PrerenderContents::PrepareForUse() {
 719   SetFinalStatus(FINAL_STATUS_USED);
 720
 721   if (prerender_contents_.get()) {
 722     prerender_contents_->SendToAllFrames(
 723         new PrerenderMsg_SetIsPrerendering(MSG_ROUTING_NONE, false));
 724   }
 725
 726   NotifyPrerenderStop();
 727
 728   BrowserThread::PostTask(
 729       BrowserThread::IO,
 730       FROM_HERE,
 731       base::Bind(&ResumeThrottles, resource_throttles_));
 732   resource_throttles_.clear();
 733 }
 734
 735 void PrerenderContents::OnCancelPrerenderForPrinting() {
 736   Destroy(FINAL_STATUS_WINDOW_PRINT);
 737 }
 738
 739 void PrerenderContents::AddResourceThrottle(
 740     const base::WeakPtr<PrerenderResourceThrottle>& throttle) {
 741   resource_throttles_.push_back(throttle);
 742 }
 743
 744 void PrerenderContents::AddNetworkBytes(int64 bytes) {
 745   network_bytes_ += bytes;
 746 }
 747
 748 }  // namespace prerender