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// 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 "chrome/browser/browser_process.h"
#include "chrome/browser/io_thread.h"
#include "chrome/browser/net/dns_probe_service.h"
#include "chrome/browser/prefs/pref_service.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/common/pref_names.h"
#include "content/public/browser/browser_thread.h"
#include "net/base/net_errors.h"
using base::FieldTrialList;
using content::BrowserContext;
using content::BrowserThread;
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);
}
void DnsProbeCallback(
base::WeakPtr<NetErrorTabHelper> tab_helper,
DnsProbeService::Result result) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
BrowserThread::PostTask(
BrowserThread::UI,
FROM_HERE,
base::Bind(&NetErrorTabHelper::OnDnsProbeFinished,
tab_helper,
result));
}
void StartDnsProbe(
base::WeakPtr<NetErrorTabHelper> tab_helper,
IOThread* io_thread) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
DnsProbeService* probe_service =
io_thread->globals()->dns_probe_service.get();
probe_service->ProbeDns(base::Bind(&DnsProbeCallback, tab_helper));
}
} // namespace
NetErrorTabHelper::NetErrorTabHelper(WebContents* contents)
: WebContentsObserver(contents),
dns_probe_running_(false),
enabled_by_trial_(GetEnabledByTrial()),
pref_initialized_(false),
ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
InitializePref(contents);
}
void NetErrorTabHelper::InitializePref(WebContents* contents) {
// Unit tests don't pass a WebContents, so the tab helper has no way to get
// to the preference. pref_initialized_ will remain false, so ProbesAllowed
// will return false without checking the pref.
if (!contents)
return;
BrowserContext* browser_context = contents->GetBrowserContext();
Profile* profile = Profile::FromBrowserContext(browser_context);
resolve_errors_with_web_service_.Init(
prefs::kAlternateErrorPagesEnabled,
profile->GetPrefs());
pref_initialized_ = true;
}
NetErrorTabHelper::~NetErrorTabHelper() {
}
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));
// Consider running a DNS probe if a main frame load fails with a DNS error
if (is_main_frame && IsDnsError(error_code))
OnMainFrameDnsError();
}
void NetErrorTabHelper::OnMainFrameDnsError() {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
// Don't start a probe if one is running already or we're not allowed to.
if (dns_probe_running_ || !ProbesAllowed())
return;
PostStartDnsProbeTask();
set_dns_probe_running(true);
}
void NetErrorTabHelper::OnDnsProbeFinished(
DnsProbeService::Result result) {
DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
DCHECK(dns_probe_running_);
// TODO(ttuttle): Notify renderer of probe results.
set_dns_probe_running(false);
}
void NetErrorTabHelper::PostStartDnsProbeTask() {
BrowserThread::PostTask(
BrowserThread::IO,
FROM_HERE,
base::Bind(&StartDnsProbe,
weak_factory_.GetWeakPtr(),
g_browser_process->io_thread()));
}
bool NetErrorTabHelper::ProbesAllowed() const {
if (testing_state_ != TESTING_DEFAULT)
return testing_state_ == TESTING_FORCE_ENABLED;
// TODO(ttuttle): Disable on mobile?
return enabled_by_trial_
&& pref_initialized_
&& *resolve_errors_with_web_service_;
}
// static
void NetErrorTabHelper::set_state_for_testing(TestingState state) {
testing_state_ = state;
}
} // namespace chrome_browser_net
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