Display DNS probe results.

chrome/browser/net/net_error_tab_helper.cc

 // Copyright (c) 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/net/net_error_tab_helper.h"
 
 #include "base/bind.h"
 #include "base/metrics/field_trial.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/io_thread.h"
 #include "chrome/browser/net/dns_probe_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/net/net_error_info.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/render_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/net_errors.h"
 
 using base::FieldTrialList;
-using chrome_common_net::DnsProbeResult;
+using chrome_common_net::DnsProbeStatus;
+using chrome_common_net::DnsProbeStatusToString;
 using content::BrowserContext;
 using content::BrowserThread;
 using content::PageTransition;
 using content::RenderViewHost;
 using content::WebContents;
 using content::WebContentsObserver;
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(chrome_browser_net::NetErrorTabHelper);
 
 namespace chrome_browser_net {
 
 namespace {
 
-const char kDnsProbeFieldTrialName[] = "DnsProbe-Enable";
-const char kDnsProbeFieldTrialEnableGroupName[] = "enable";
-
 static NetErrorTabHelper::TestingState testing_state_ =
     NetErrorTabHelper::TESTING_DEFAULT;
 
 // Returns whether |net_error| is a DNS-related error (and therefore whether
 // the tab helper should start a DNS probe after receiving it.)
 bool IsDnsError(int net_error) {
   return net_error == net::ERR_NAME_NOT_RESOLVED ||
          net_error == net::ERR_NAME_RESOLUTION_FAILED;
 }
 
-bool GetEnabledByTrial() {
-  return (FieldTrialList::FindFullName(kDnsProbeFieldTrialName)
-          == kDnsProbeFieldTrialEnableGroupName);
-}
-
-NetErrorTracker::FrameType GetFrameType(bool is_main_frame) {
-  return is_main_frame ? NetErrorTracker::FRAME_MAIN
-                       : NetErrorTracker::FRAME_SUB;
-}
-
-NetErrorTracker::PageType GetPageType(bool is_error_page) {
-  return is_error_page ? NetErrorTracker::PAGE_ERROR
-                       : NetErrorTracker::PAGE_NORMAL;
-}
-
-NetErrorTracker::ErrorType GetErrorType(int net_error) {
-  return IsDnsError(net_error) ? NetErrorTracker::ERROR_DNS
-                               : NetErrorTracker::ERROR_OTHER;
-}
-
 void OnDnsProbeFinishedOnIOThread(
-    const base::Callback<void(DnsProbeResult)>& callback,
-    DnsProbeResult result) {
+    const base::Callback<void(DnsProbeStatus)>& callback,
+    DnsProbeStatus result) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
-  DVLOG(1) << "DNS probe finished with result " << result;
-
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
       base::Bind(callback, result));
 }
 
-// We can only access g_browser_process->io_thread() from the browser thread,
-// so we have to pass it in to the callback instead of dereferencing it here.
+// Can only access g_browser_process->io_thread() from the browser thread,
+// so have to pass it in to the callback instead of dereferencing it here.
 void StartDnsProbeOnIOThread(
-    const base::Callback<void(DnsProbeResult)>& callback,
+    const base::Callback<void(DnsProbeStatus)>& callback,
     IOThread* io_thread) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
-  DVLOG(1) << "Starting DNS probe";
-
   DnsProbeService* probe_service =
       io_thread->globals()->dns_probe_service.get();
 
   probe_service->ProbeDns(base::Bind(&OnDnsProbeFinishedOnIOThread, callback));
 }
 
 }  // namespace
 
 NetErrorTabHelper::~NetErrorTabHelper() {
 }
 
 // static
 void NetErrorTabHelper::set_state_for_testing(TestingState state) {
   testing_state_ = state;
 }
 
 void NetErrorTabHelper::DidStartProvisionalLoadForFrame(
     int64 frame_id,
     int64 parent_frame_id,
     bool is_main_frame,
     const GURL& validated_url,
     bool is_error_page,
     bool is_iframe_srcdoc,
     RenderViewHost* render_view_host) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  tracker_.OnStartProvisionalLoad(GetFrameType(is_main_frame),
-                                  GetPageType(is_error_page));
+  if (!is_main_frame)
+    return;
+
+  is_error_page_ = is_error_page;
 }
 
 void NetErrorTabHelper::DidCommitProvisionalLoadForFrame(
     int64 frame_id,
     bool is_main_frame,
     const GURL& url,
     PageTransition transition_type,
     RenderViewHost* render_view_host) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  tracker_.OnCommitProvisionalLoad(GetFrameType(is_main_frame));
+  if (!is_main_frame)
+    return;
+
+  // Resend status every time an error page commits; this is somewhat spammy,
+  // but ensures that the status will make it to the real error page, even if
+  // the link doctor loads a blank intermediate page or the tab switches
+  // renderer processes.
+  if (is_error_page_ && dns_error_active_) {
+    dns_error_page_committed_ = true;
+    DVLOG(1) << "Committed error page; resending status.";
+    SendInfo();
+  } else {
+    dns_error_active_ = false;
+    dns_error_page_committed_ = false;
+  }
 }
 
 void NetErrorTabHelper::DidFailProvisionalLoad(
     int64 frame_id,
     bool is_main_frame,
     const GURL& validated_url,
     int error_code,
     const string16& error_description,
     RenderViewHost* render_view_host) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  tracker_.OnFailProvisionalLoad(GetFrameType(is_main_frame),
-                                 GetErrorType(error_code));
-}
+  if (!is_main_frame)
+    return;
 
-void NetErrorTabHelper::DidFinishLoad(
-    int64 frame_id,
-    const GURL& validated_url,
-    bool is_main_frame,
-    RenderViewHost* render_view_host) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  tracker_.OnFinishLoad(GetFrameType(is_main_frame));
+  if (IsDnsError(error_code)) {
+    dns_error_active_ = true;
+    OnMainFrameDnsError();
+  }
 }
 
 NetErrorTabHelper::NetErrorTabHelper(WebContents* contents)
     : WebContentsObserver(contents),
       weak_factory_(this),
-      tracker_(base::Bind(&NetErrorTabHelper::TrackerCallback,
-                          weak_factory_.GetWeakPtr())),
-      dns_error_page_state_(NetErrorTracker::DNS_ERROR_PAGE_NONE),
-      dns_probe_state_(DNS_PROBE_NONE),
-      enabled_by_trial_(GetEnabledByTrial()) {
+      is_error_page_(false),
+      dns_error_active_(false),
+      dns_error_page_committed_(false),
+      dns_probe_status_(chrome_common_net::DNS_PROBE_POSSIBLE),
+      enabled_by_trial_(chrome_common_net::DnsProbesEnabledByFieldTrial()) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  InitializePref(contents);
+  // If this helper is under test, it won't have a WebContents.
+  if (contents)
+    InitializePref(contents);
 }
 
-void NetErrorTabHelper::TrackerCallback(
-    NetErrorTracker::DnsErrorPageState state) {
-  dns_error_page_state_ = state;
-
-  MaybePostStartDnsProbeTask();
-  MaybeSendInfo();
-}
-
-void NetErrorTabHelper::MaybePostStartDnsProbeTask() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-
-  if (dns_error_page_state_ != NetErrorTracker::DNS_ERROR_PAGE_NONE &&
-      dns_probe_state_ != DNS_PROBE_STARTED &&
-      ProbesAllowed()) {
-    BrowserThread::PostTask(
-        BrowserThread::IO,
-        FROM_HERE,
-        base::Bind(&StartDnsProbeOnIOThread,
-                   base::Bind(&NetErrorTabHelper::OnDnsProbeFinished,
-                              weak_factory_.GetWeakPtr()),
-                   g_browser_process->io_thread()));
-    dns_probe_state_ = DNS_PROBE_STARTED;
+void NetErrorTabHelper::OnMainFrameDnsError() {
+  if (ProbesAllowed()) {
+    // Don't start more than one probe at a time.
+    if (dns_probe_status_ != chrome_common_net::DNS_PROBE_STARTED) {
+      StartDnsProbe();
+      dns_probe_status_ = chrome_common_net::DNS_PROBE_STARTED;
+    }
+  } else {
+    dns_probe_status_ = chrome_common_net::DNS_PROBE_NOT_RUN;
   }
 }
 
-void NetErrorTabHelper::OnDnsProbeFinished(DnsProbeResult result) {
+void NetErrorTabHelper::StartDnsProbe() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK_EQ(DNS_PROBE_STARTED, dns_probe_state_);
+  DCHECK(dns_error_active_);
+  DCHECK_NE(chrome_common_net::DNS_PROBE_STARTED, dns_probe_status_);
 
-  dns_probe_result_ = result;
-  dns_probe_state_ = DNS_PROBE_FINISHED;
+  DVLOG(1) << "Starting DNS probe.";
 
-  MaybeSendInfo();
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&StartDnsProbeOnIOThread,
+                 base::Bind(&NetErrorTabHelper::OnDnsProbeFinished,
+                            weak_factory_.GetWeakPtr()),
+                 g_browser_process->io_thread()));
 }
 
-void NetErrorTabHelper::MaybeSendInfo() {
-  if (dns_error_page_state_ == NetErrorTracker::DNS_ERROR_PAGE_LOADED &&
-      dns_probe_state_ == DNS_PROBE_FINISHED) {
-    DVLOG(1) << "Sending result " << dns_probe_result_ << " to renderer";
-    Send(new ChromeViewMsg_NetErrorInfo(routing_id(), dns_probe_result_));
-    dns_probe_state_ = DNS_PROBE_NONE;
-  }
+void NetErrorTabHelper::OnDnsProbeFinished(DnsProbeStatus result) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK_EQ(chrome_common_net::DNS_PROBE_STARTED, dns_probe_status_);
+  DCHECK(chrome_common_net::DnsProbeStatusIsFinished(result));
+
+  DVLOG(1) << "Finished DNS probe with result "
+           << DnsProbeStatusToString(result) << ".";
+
+  dns_probe_status_ = result;
+
+  if (dns_error_page_committed_)
+    SendInfo();
 }
 
 void NetErrorTabHelper::InitializePref(WebContents* contents) {
   DCHECK(contents);
 
   BrowserContext* browser_context = contents->GetBrowserContext();
   Profile* profile = Profile::FromBrowserContext(browser_context);
   resolve_errors_with_web_service_.Init(
       prefs::kAlternateErrorPagesEnabled,
       profile->GetPrefs());
 }
 
 bool NetErrorTabHelper::ProbesAllowed() const {
   if (testing_state_ != TESTING_DEFAULT)
     return testing_state_ == TESTING_FORCE_ENABLED;
 
   // TODO(ttuttle): Disable on mobile?
   return enabled_by_trial_ && *resolve_errors_with_web_service_;
 }
 
+void NetErrorTabHelper::SendInfo() {
+  DCHECK_NE(chrome_common_net::DNS_PROBE_POSSIBLE, dns_probe_status_);
+  DCHECK(dns_error_page_committed_);
+
+  DVLOG(1) << "Sending status " << DnsProbeStatusToString(dns_probe_status_);
+  Send(new ChromeViewMsg_NetErrorInfo(routing_id(), dns_probe_status_));
+
+  if (!dns_probe_status_snoop_callback_.is_null())
+    dns_probe_status_snoop_callback_.Run(dns_probe_status_);
+}
+
 }  // namespace chrome_browser_net