chrome/renderer/net/net_error_helper.cc - chromium/src - Git at Google

 // Copyright (c) 2013 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/renderer/net/net_error_helper.h"

 #include <string>

 #include "base/command_line.h"
 #include "base/i18n/rtl.h"
 #include "base/json/json_writer.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/localized_error.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/grit/renderer_resources.h"
 #include "chrome/renderer/net/net_error_page_controller.h"
 #include "components/error_page/common/error_page_params.h"
 #include "components/error_page/common/net_error_info.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/renderer/content_renderer_client.h"
 #include "content/public/renderer/document_state.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/render_view.h"
 #include "content/public/renderer/resource_fetcher.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_message_macros.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/platform/WebURLError.h"
 #include "third_party/WebKit/public/platform/WebURLRequest.h"
 #include "third_party/WebKit/public/platform/WebURLResponse.h"
 #include "third_party/WebKit/public/web/WebDataSource.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebView.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/webui/jstemplate_builder.h"
 #include "url/gurl.h"

 using base::JSONWriter;
 using chrome_common_net::DnsProbeStatus;
 using chrome_common_net::DnsProbeStatusToString;
 using content::DocumentState;
 using content::RenderFrame;
 using content::RenderFrameObserver;
 using content::RenderThread;
 using content::kUnreachableWebDataURL;
 using error_page::ErrorPageParams;
 using error_page::NetErrorHelperCore;

 namespace {

 // Number of seconds to wait for the navigation correction service to return
 // suggestions.  If it takes too long, just use the local error page.
 static const int kNavigationCorrectionFetchTimeoutSec = 3;

 NetErrorHelperCore::PageType GetLoadingPageType(const blink::WebFrame* frame) {
   GURL url = frame->provisionalDataSource()->request().url();
   if (!url.is_valid() || url.spec() != kUnreachableWebDataURL)
     return NetErrorHelperCore::NON_ERROR_PAGE;
   return NetErrorHelperCore::ERROR_PAGE;
 }

 NetErrorHelperCore::FrameType GetFrameType(const blink::WebFrame* frame) {
   if (!frame->parent())
     return NetErrorHelperCore::MAIN_FRAME;
   return NetErrorHelperCore::SUB_FRAME;
 }

 }  // namespace

 NetErrorHelper::NetErrorHelper(RenderFrame* render_frame)
     : RenderFrameObserver(render_frame),
       content::RenderFrameObserverTracker<NetErrorHelper>(render_frame) {
   RenderThread::Get()->AddObserver(this);
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   bool auto_reload_enabled =
       command_line->HasSwitch(switches::kEnableOfflineAutoReload);
   bool auto_reload_visible_only =
       command_line->HasSwitch(switches::kEnableOfflineAutoReloadVisibleOnly);
   core_.reset(new NetErrorHelperCore(this,
                                      auto_reload_enabled,
                                      auto_reload_visible_only,
                                      !render_frame->IsHidden()));
 }

 NetErrorHelper::~NetErrorHelper() {
   RenderThread::Get()->RemoveObserver(this);
 }

 void NetErrorHelper::ReloadButtonPressed() {
   core_->ExecuteButtonPress(NetErrorHelperCore::RELOAD_BUTTON);
 }

 void NetErrorHelper::ShowSavedCopyButtonPressed() {
   core_->ExecuteButtonPress(NetErrorHelperCore::SHOW_SAVED_COPY_BUTTON);
 }

 void NetErrorHelper::MoreButtonPressed() {
   core_->ExecuteButtonPress(NetErrorHelperCore::MORE_BUTTON);
 }

 void NetErrorHelper::TrackActivatedEasterEgg() {
   core_->ExecuteButtonPress(NetErrorHelperCore::EASTER_EGG);
 }

 void NetErrorHelper::DidStartProvisionalLoad() {
   blink::WebFrame* frame = render_frame()->GetWebFrame();
   core_->OnStartLoad(GetFrameType(frame), GetLoadingPageType(frame));
 }

 void NetErrorHelper::DidCommitProvisionalLoad(bool is_new_navigation,
                                               bool is_same_page_navigation) {
   blink::WebFrame* frame = render_frame()->GetWebFrame();
   core_->OnCommitLoad(GetFrameType(frame), frame->document().url());
 }

 void NetErrorHelper::DidFinishLoad() {
   blink::WebFrame* frame = render_frame()->GetWebFrame();
   core_->OnFinishLoad(GetFrameType(frame));
 }

 void NetErrorHelper::OnStop() {
   core_->OnStop();
 }

 void NetErrorHelper::WasShown() {
   core_->OnWasShown();
 }

 void NetErrorHelper::WasHidden() {
   core_->OnWasHidden();
 }

 bool NetErrorHelper::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;

   IPC_BEGIN_MESSAGE_MAP(NetErrorHelper, message)
     IPC_MESSAGE_HANDLER(ChromeViewMsg_NetErrorInfo, OnNetErrorInfo)
     IPC_MESSAGE_HANDLER(ChromeViewMsg_SetNavigationCorrectionInfo,
                         OnSetNavigationCorrectionInfo);
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()

   return handled;
 }

 void NetErrorHelper::NetworkStateChanged(bool enabled) {
   core_->NetworkStateChanged(enabled);
 }

 void NetErrorHelper::GetErrorHTML(
     blink::WebFrame* frame,
     const blink::WebURLError& error,
     bool is_failed_post,
     std::string* error_html) {
   core_->GetErrorHTML(GetFrameType(frame), error, is_failed_post, error_html);
 }

 bool NetErrorHelper::ShouldSuppressErrorPage(blink::WebFrame* frame,
                                              const GURL& url) {
   return core_->ShouldSuppressErrorPage(GetFrameType(frame), url);
 }

 void NetErrorHelper::TrackClick(int tracking_id) {
   core_->TrackClick(tracking_id);
 }

 void NetErrorHelper::GenerateLocalizedErrorPage(
     const blink::WebURLError& error,
     bool is_failed_post,
     scoped_ptr<ErrorPageParams> params,
     bool* reload_button_shown,
     bool* show_saved_copy_button_shown,
     std::string* error_html) const {
   error_html->clear();

   int resource_id = IDR_NET_ERROR_HTML;
   const base::StringPiece template_html(
       ResourceBundle::GetSharedInstance().GetRawDataResource(resource_id));
   if (template_html.empty()) {
     NOTREACHED() << "unable to load template.";
   } else {
     base::DictionaryValue error_strings;
     LocalizedError::GetStrings(error.reason, error.domain.utf8(),
                                error.unreachableURL, is_failed_post,
                                error.staleCopyInCache,
                                RenderThread::Get()->GetLocale(),
                                render_frame()->GetRenderView()->
                                    GetAcceptLanguages(),
                                params.Pass(), &error_strings);
     *reload_button_shown = error_strings.Get("reloadButton", NULL);
     *show_saved_copy_button_shown =
         error_strings.Get("showSavedCopyButton", NULL);

     // "t" is the id of the template's root node.
     *error_html = webui::GetTemplatesHtml(template_html, &error_strings, "t");
   }
 }

 void NetErrorHelper::LoadErrorPageInMainFrame(const std::string& html,
                                               const GURL& failed_url) {
   blink::WebView* web_view = render_frame()->GetRenderView()->GetWebView();
   if (!web_view)
     return;
   blink::WebFrame* frame = web_view->mainFrame();
   frame->loadHTMLString(html, GURL(kUnreachableWebDataURL), failed_url, true);
 }

 void NetErrorHelper::EnablePageHelperFunctions() {
   NetErrorPageController::Install(render_frame());
 }

 void NetErrorHelper::UpdateErrorPage(const blink::WebURLError& error,
                                      bool is_failed_post) {
   base::DictionaryValue error_strings;
   LocalizedError::GetStrings(error.reason,
                              error.domain.utf8(),
                              error.unreachableURL,
                              is_failed_post,
                              error.staleCopyInCache,
                              RenderThread::Get()->GetLocale(),
                              render_frame()->GetRenderView()->
                                  GetAcceptLanguages(),
                              scoped_ptr<ErrorPageParams>(),
                              &error_strings);

   std::string json;
   JSONWriter::Write(error_strings, &json);

   std::string js = "if (window.updateForDnsProbe) "
                    "updateForDnsProbe(" + json + ");";
   base::string16 js16;
   if (!base::UTF8ToUTF16(js.c_str(), js.length(), &js16)) {
     NOTREACHED();
     return;
   }

   render_frame()->ExecuteJavaScript(js16);
 }

 void NetErrorHelper::FetchNavigationCorrections(
     const GURL& navigation_correction_url,
     const std::string& navigation_correction_request_body) {
   DCHECK(!correction_fetcher_.get());

   blink::WebView* web_view = render_frame()->GetRenderView()->GetWebView();
   if (!web_view)
     return;
   blink::WebFrame* frame = web_view->mainFrame();

   correction_fetcher_.reset(
       content::ResourceFetcher::Create(navigation_correction_url));
   correction_fetcher_->SetMethod("POST");
   correction_fetcher_->SetBody(navigation_correction_request_body);
   correction_fetcher_->SetHeader("Content-Type", "application/json");

   correction_fetcher_->Start(
       frame,
       blink::WebURLRequest::RequestContextInternal,
       blink::WebURLRequest::FrameTypeTopLevel,
       content::ResourceFetcher::PLATFORM_LOADER,
       base::Bind(&NetErrorHelper::OnNavigationCorrectionsFetched,
                  base::Unretained(this)));

   correction_fetcher_->SetTimeout(
       base::TimeDelta::FromSeconds(kNavigationCorrectionFetchTimeoutSec));
 }

 void NetErrorHelper::CancelFetchNavigationCorrections() {
   correction_fetcher_.reset();
 }

 void NetErrorHelper::SendTrackingRequest(
     const GURL& tracking_url,
     const std::string& tracking_request_body) {
   blink::WebView* web_view = render_frame()->GetRenderView()->GetWebView();
   if (!web_view)
     return;
   blink::WebFrame* frame = web_view->mainFrame();

   // If there's already a pending tracking request, this will cancel it.
   tracking_fetcher_.reset(content::ResourceFetcher::Create(tracking_url));
   tracking_fetcher_->SetMethod("POST");
   tracking_fetcher_->SetBody(tracking_request_body);
   tracking_fetcher_->SetHeader("Content-Type", "application/json");

   tracking_fetcher_->Start(
       frame,
       blink::WebURLRequest::RequestContextInternal,
       blink::WebURLRequest::FrameTypeTopLevel,
       content::ResourceFetcher::PLATFORM_LOADER,
       base::Bind(&NetErrorHelper::OnTrackingRequestComplete,
                  base::Unretained(this)));
 }

 void NetErrorHelper::ReloadPage() {
   render_frame()->GetWebFrame()->reload(false);
 }

 void NetErrorHelper::LoadPageFromCache(const GURL& page_url) {
   blink::WebFrame* web_frame = render_frame()->GetWebFrame();
   DCHECK(!EqualsASCII(web_frame->dataSource()->request().httpMethod(), "POST"));

   blink::WebURLRequest request(page_url);
   request.setCachePolicy(blink::WebURLRequest::ReturnCacheDataDontLoad);

   web_frame->loadRequest(request);
 }

 void NetErrorHelper::OnNetErrorInfo(int status_num) {
   DCHECK(status_num >= 0 && status_num < chrome_common_net::DNS_PROBE_MAX);

   DVLOG(1) << "Received status " << DnsProbeStatusToString(status_num);

   core_->OnNetErrorInfo(static_cast<DnsProbeStatus>(status_num));
 }

 void NetErrorHelper::OnSetNavigationCorrectionInfo(
     const GURL& navigation_correction_url,
     const std::string& language,
     const std::string& country_code,
     const std::string& api_key,
     const GURL& search_url) {
   core_->OnSetNavigationCorrectionInfo(navigation_correction_url, language,
                                       country_code, api_key, search_url);
 }

 void NetErrorHelper::OnNavigationCorrectionsFetched(
     const blink::WebURLResponse& response,
     const std::string& data) {
   // The fetcher may only be deleted after |data| is passed to |core_|.  Move
   // it to a temporary to prevent any potential re-entrancy issues.
   scoped_ptr<content::ResourceFetcher> fetcher(
       correction_fetcher_.release());
   bool success = (!response.isNull() && response.httpStatusCode() == 200);
   core_->OnNavigationCorrectionsFetched(
       success ? data : "",
       render_frame()->GetRenderView()->GetAcceptLanguages(),
       base::i18n::IsRTL());
 }

 void NetErrorHelper::OnTrackingRequestComplete(
     const blink::WebURLResponse& response,
     const std::string& data) {
   tracking_fetcher_.reset();
 }
	// Copyright (c) 2013 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/renderer/net/net_error_helper.h"

	#include <string>

	#include "base/command_line.h"
	#include "base/i18n/rtl.h"
	#include "base/json/json_writer.h"
	#include "base/metrics/histogram.h"
	#include "base/strings/utf_string_conversions.h"
	#include "base/values.h"
	#include "chrome/common/chrome_switches.h"
	#include "chrome/common/localized_error.h"
	#include "chrome/common/render_messages.h"
	#include "chrome/grit/renderer_resources.h"
	#include "chrome/renderer/net/net_error_page_controller.h"
	#include "components/error_page/common/error_page_params.h"
	#include "components/error_page/common/net_error_info.h"
	#include "content/public/common/content_client.h"
	#include "content/public/common/url_constants.h"
	#include "content/public/renderer/content_renderer_client.h"
	#include "content/public/renderer/document_state.h"
	#include "content/public/renderer/render_frame.h"
	#include "content/public/renderer/render_thread.h"
	#include "content/public/renderer/render_view.h"
	#include "content/public/renderer/resource_fetcher.h"
	#include "ipc/ipc_message.h"
	#include "ipc/ipc_message_macros.h"
	#include "third_party/WebKit/public/platform/WebURL.h"
	#include "third_party/WebKit/public/platform/WebURLError.h"
	#include "third_party/WebKit/public/platform/WebURLRequest.h"
	#include "third_party/WebKit/public/platform/WebURLResponse.h"
	#include "third_party/WebKit/public/web/WebDataSource.h"
	#include "third_party/WebKit/public/web/WebDocument.h"
	#include "third_party/WebKit/public/web/WebLocalFrame.h"
	#include "third_party/WebKit/public/web/WebView.h"
	#include "ui/base/resource/resource_bundle.h"
	#include "ui/base/webui/jstemplate_builder.h"
	#include "url/gurl.h"

	using base::JSONWriter;
	using chrome_common_net::DnsProbeStatus;
	using chrome_common_net::DnsProbeStatusToString;
	using content::DocumentState;
	using content::RenderFrame;
	using content::RenderFrameObserver;
	using content::RenderThread;
	using content::kUnreachableWebDataURL;
	using error_page::ErrorPageParams;
	using error_page::NetErrorHelperCore;

	namespace {

	// Number of seconds to wait for the navigation correction service to return
	// suggestions. If it takes too long, just use the local error page.
	static const int kNavigationCorrectionFetchTimeoutSec = 3;

	NetErrorHelperCore::PageType GetLoadingPageType(const blink::WebFrame* frame) {
	GURL url = frame->provisionalDataSource()->request().url();
	if (!url.is_valid() \|\| url.spec() != kUnreachableWebDataURL)
	return NetErrorHelperCore::NON_ERROR_PAGE;
	return NetErrorHelperCore::ERROR_PAGE;
	}

	NetErrorHelperCore::FrameType GetFrameType(const blink::WebFrame* frame) {
	if (!frame->parent())
	return NetErrorHelperCore::MAIN_FRAME;
	return NetErrorHelperCore::SUB_FRAME;
	}

	} // namespace

	NetErrorHelper::NetErrorHelper(RenderFrame* render_frame)
	: RenderFrameObserver(render_frame),
	content::RenderFrameObserverTracker<NetErrorHelper>(render_frame) {
	RenderThread::Get()->AddObserver(this);
	base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
	bool auto_reload_enabled =
	command_line->HasSwitch(switches::kEnableOfflineAutoReload);
	bool auto_reload_visible_only =
	command_line->HasSwitch(switches::kEnableOfflineAutoReloadVisibleOnly);
	core_.reset(new NetErrorHelperCore(this,
	auto_reload_enabled,
	auto_reload_visible_only,
	!render_frame->IsHidden()));
	}

	NetErrorHelper::~NetErrorHelper() {
	RenderThread::Get()->RemoveObserver(this);
	}

	void NetErrorHelper::ReloadButtonPressed() {
	core_->ExecuteButtonPress(NetErrorHelperCore::RELOAD_BUTTON);
	}

	void NetErrorHelper::ShowSavedCopyButtonPressed() {
	core_->ExecuteButtonPress(NetErrorHelperCore::SHOW_SAVED_COPY_BUTTON);
	}

	void NetErrorHelper::MoreButtonPressed() {
	core_->ExecuteButtonPress(NetErrorHelperCore::MORE_BUTTON);
	}

	void NetErrorHelper::TrackActivatedEasterEgg() {
	core_->ExecuteButtonPress(NetErrorHelperCore::EASTER_EGG);
	}

	void NetErrorHelper::DidStartProvisionalLoad() {
	blink::WebFrame* frame = render_frame()->GetWebFrame();
	core_->OnStartLoad(GetFrameType(frame), GetLoadingPageType(frame));
	}

	void NetErrorHelper::DidCommitProvisionalLoad(bool is_new_navigation,
	bool is_same_page_navigation) {
	blink::WebFrame* frame = render_frame()->GetWebFrame();
	core_->OnCommitLoad(GetFrameType(frame), frame->document().url());
	}

	void NetErrorHelper::DidFinishLoad() {
	blink::WebFrame* frame = render_frame()->GetWebFrame();
	core_->OnFinishLoad(GetFrameType(frame));
	}

	void NetErrorHelper::OnStop() {
	core_->OnStop();
	}

	void NetErrorHelper::WasShown() {
	core_->OnWasShown();
	}

	void NetErrorHelper::WasHidden() {
	core_->OnWasHidden();
	}

	bool NetErrorHelper::OnMessageReceived(const IPC::Message& message) {
	bool handled = true;

	IPC_BEGIN_MESSAGE_MAP(NetErrorHelper, message)
	IPC_MESSAGE_HANDLER(ChromeViewMsg_NetErrorInfo, OnNetErrorInfo)
	IPC_MESSAGE_HANDLER(ChromeViewMsg_SetNavigationCorrectionInfo,
	OnSetNavigationCorrectionInfo);
	IPC_MESSAGE_UNHANDLED(handled = false)
	IPC_END_MESSAGE_MAP()

	return handled;
	}

	void NetErrorHelper::NetworkStateChanged(bool enabled) {
	core_->NetworkStateChanged(enabled);
	}

	void NetErrorHelper::GetErrorHTML(
	blink::WebFrame* frame,
	const blink::WebURLError& error,
	bool is_failed_post,
	std::string* error_html) {
	core_->GetErrorHTML(GetFrameType(frame), error, is_failed_post, error_html);
	}

	bool NetErrorHelper::ShouldSuppressErrorPage(blink::WebFrame* frame,
	const GURL& url) {
	return core_->ShouldSuppressErrorPage(GetFrameType(frame), url);
	}

	void NetErrorHelper::TrackClick(int tracking_id) {
	core_->TrackClick(tracking_id);
	}

	void NetErrorHelper::GenerateLocalizedErrorPage(
	const blink::WebURLError& error,
	bool is_failed_post,
	scoped_ptr<ErrorPageParams> params,
	bool* reload_button_shown,
	bool* show_saved_copy_button_shown,
	std::string* error_html) const {
	error_html->clear();

	int resource_id = IDR_NET_ERROR_HTML;
	const base::StringPiece template_html(
	ResourceBundle::GetSharedInstance().GetRawDataResource(resource_id));
	if (template_html.empty()) {
	NOTREACHED() << "unable to load template.";
	} else {
	base::DictionaryValue error_strings;
	LocalizedError::GetStrings(error.reason, error.domain.utf8(),
	error.unreachableURL, is_failed_post,
	error.staleCopyInCache,
	RenderThread::Get()->GetLocale(),
	render_frame()->GetRenderView()->
	GetAcceptLanguages(),
	params.Pass(), &error_strings);
	*reload_button_shown = error_strings.Get("reloadButton", NULL);
	*show_saved_copy_button_shown =
	error_strings.Get("showSavedCopyButton", NULL);

	// "t" is the id of the template's root node.
	*error_html = webui::GetTemplatesHtml(template_html, &error_strings, "t");
	}
	}

	void NetErrorHelper::LoadErrorPageInMainFrame(const std::string& html,
	const GURL& failed_url) {
	blink::WebView* web_view = render_frame()->GetRenderView()->GetWebView();
	if (!web_view)
	return;
	blink::WebFrame* frame = web_view->mainFrame();
	frame->loadHTMLString(html, GURL(kUnreachableWebDataURL), failed_url, true);
	}

	void NetErrorHelper::EnablePageHelperFunctions() {
	NetErrorPageController::Install(render_frame());
	}

	void NetErrorHelper::UpdateErrorPage(const blink::WebURLError& error,
	bool is_failed_post) {
	base::DictionaryValue error_strings;
	LocalizedError::GetStrings(error.reason,
	error.domain.utf8(),
	error.unreachableURL,
	is_failed_post,
	error.staleCopyInCache,
	RenderThread::Get()->GetLocale(),
	render_frame()->GetRenderView()->
	GetAcceptLanguages(),
	scoped_ptr<ErrorPageParams>(),
	&error_strings);

	std::string json;
	JSONWriter::Write(error_strings, &json);

	std::string js = "if (window.updateForDnsProbe) "
	"updateForDnsProbe(" + json + ");";
	base::string16 js16;
	if (!base::UTF8ToUTF16(js.c_str(), js.length(), &js16)) {
	NOTREACHED();
	return;
	}

	render_frame()->ExecuteJavaScript(js16);
	}

	void NetErrorHelper::FetchNavigationCorrections(
	const GURL& navigation_correction_url,
	const std::string& navigation_correction_request_body) {
	DCHECK(!correction_fetcher_.get());

	blink::WebView* web_view = render_frame()->GetRenderView()->GetWebView();
	if (!web_view)
	return;
	blink::WebFrame* frame = web_view->mainFrame();

	correction_fetcher_.reset(
	content::ResourceFetcher::Create(navigation_correction_url));
	correction_fetcher_->SetMethod("POST");
	correction_fetcher_->SetBody(navigation_correction_request_body);
	correction_fetcher_->SetHeader("Content-Type", "application/json");

	correction_fetcher_->Start(
	frame,
	blink::WebURLRequest::RequestContextInternal,
	blink::WebURLRequest::FrameTypeTopLevel,
	content::ResourceFetcher::PLATFORM_LOADER,
	base::Bind(&NetErrorHelper::OnNavigationCorrectionsFetched,
	base::Unretained(this)));

	correction_fetcher_->SetTimeout(
	base::TimeDelta::FromSeconds(kNavigationCorrectionFetchTimeoutSec));
	}

	void NetErrorHelper::CancelFetchNavigationCorrections() {
	correction_fetcher_.reset();
	}

	void NetErrorHelper::SendTrackingRequest(
	const GURL& tracking_url,
	const std::string& tracking_request_body) {
	blink::WebView* web_view = render_frame()->GetRenderView()->GetWebView();
	if (!web_view)
	return;
	blink::WebFrame* frame = web_view->mainFrame();

	// If there's already a pending tracking request, this will cancel it.
	tracking_fetcher_.reset(content::ResourceFetcher::Create(tracking_url));
	tracking_fetcher_->SetMethod("POST");
	tracking_fetcher_->SetBody(tracking_request_body);
	tracking_fetcher_->SetHeader("Content-Type", "application/json");

	tracking_fetcher_->Start(
	frame,
	blink::WebURLRequest::RequestContextInternal,
	blink::WebURLRequest::FrameTypeTopLevel,
	content::ResourceFetcher::PLATFORM_LOADER,
	base::Bind(&NetErrorHelper::OnTrackingRequestComplete,
	base::Unretained(this)));
	}

	void NetErrorHelper::ReloadPage() {
	render_frame()->GetWebFrame()->reload(false);
	}

	void NetErrorHelper::LoadPageFromCache(const GURL& page_url) {
	blink::WebFrame* web_frame = render_frame()->GetWebFrame();
	DCHECK(!EqualsASCII(web_frame->dataSource()->request().httpMethod(), "POST"));

	blink::WebURLRequest request(page_url);
	request.setCachePolicy(blink::WebURLRequest::ReturnCacheDataDontLoad);

	web_frame->loadRequest(request);
	}

	void NetErrorHelper::OnNetErrorInfo(int status_num) {
	DCHECK(status_num >= 0 && status_num < chrome_common_net::DNS_PROBE_MAX);

	DVLOG(1) << "Received status " << DnsProbeStatusToString(status_num);

	core_->OnNetErrorInfo(static_cast<DnsProbeStatus>(status_num));
	}

	void NetErrorHelper::OnSetNavigationCorrectionInfo(
	const GURL& navigation_correction_url,
	const std::string& language,
	const std::string& country_code,
	const std::string& api_key,
	const GURL& search_url) {
	core_->OnSetNavigationCorrectionInfo(navigation_correction_url, language,
	country_code, api_key, search_url);
	}

	void NetErrorHelper::OnNavigationCorrectionsFetched(
	const blink::WebURLResponse& response,
	const std::string& data) {
	// The fetcher may only be deleted after \|data\| is passed to \|core_\|. Move
	// it to a temporary to prevent any potential re-entrancy issues.
	scoped_ptr<content::ResourceFetcher> fetcher(
	correction_fetcher_.release());
	bool success = (!response.isNull() && response.httpStatusCode() == 200);
	core_->OnNavigationCorrectionsFetched(
	success ? data : "",
	render_frame()->GetRenderView()->GetAcceptLanguages(),
	base::i18n::IsRTL());
	}

	void NetErrorHelper::OnTrackingRequestComplete(
	const blink::WebURLResponse& response,
	const std::string& data) {
	tracking_fetcher_.reset();
	}