Support auto-reload on errors.

chrome/renderer/net/net_error_helper_core.cc

Index: chrome/renderer/net/net_error_helper_core.cc
diff --git a/chrome/renderer/net/net_error_helper_core.cc b/chrome/renderer/net/net_error_helper_core.cc
index 2501ec183f9bfe64abf7f978af40df8a0b093322..e517157eb04152e30e1f13065e7515c096bf5d62 100644
--- a/chrome/renderer/net/net_error_helper_core.cc
+++ b/chrome/renderer/net/net_error_helper_core.cc
@@ -6,6 +6,9 @@
 
 #include <string>
 
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/location.h"
 #include "base/metrics/histogram.h"
 #include "chrome/common/localized_error.h"
 #include "net/base/escape.h"
@@ -16,6 +19,15 @@
 
 namespace {
 
+base::TimeDelta GetAutoReloadTime(size_t reload_count) {
+  static const int kDelaysMs[] = {
+    0, 5000, 30000, 60000, 300000, 600000, 1800000
+  };
+  if (reload_count >= arraysize(kDelaysMs))
+    reload_count = arraysize(kDelaysMs) - 1;
+  return base::TimeDelta::FromMilliseconds(kDelaysMs[reload_count]);
+}
+
 // 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(const blink::WebURLError& error) {
@@ -116,23 +128,50 @@ struct NetErrorHelperCore::ErrorPageInfo {
   bool is_finished_loading;
 };
 
+bool NetErrorHelperCore::IsReloadableError(
+    const NetErrorHelperCore::ErrorPageInfo& info) {
+  return info.error.domain.utf8() == net::kErrorDomain &&
+         info.error.reason != net::ERR_ABORTED &&
+         !info.was_failed_post;
+}
+
 NetErrorHelperCore::NetErrorHelperCore(Delegate* delegate)
     : delegate_(delegate),
-      last_probe_status_(chrome_common_net::DNS_PROBE_POSSIBLE) {
+      last_probe_status_(chrome_common_net::DNS_PROBE_POSSIBLE),
+      auto_reload_enabled_(false),
+      auto_reload_timer_(new MockableOneShotTimer()),
+      online_(true),
+      auto_reload_count_(0),
+      can_auto_reload_page_(false) {
 }
 
 NetErrorHelperCore::~NetErrorHelperCore() {
 }
 
-void NetErrorHelperCore::OnStop() {
-  // On stop, cancel loading the alternate error page, and prevent any pending
-  // error page load from starting a new error page load.  Swapping in the error
-  // page when it's finished loading could abort the navigation, otherwise.
-  if (committed_error_page_info_)
+void NetErrorHelperCore::CancelPendingFetches() {
+  // Cancel loading the alternate error page, and prevent any pending error page
+  // load from starting a new error page load.  Swapping in the error page when
+  // it's finished loading could abort the navigation, otherwise.
+  if (committed_error_page_info_ && can_auto_reload_page_) {
+    UMA_HISTOGRAM_CUSTOM_ENUMERATION("Net.AutoReload.ErrorAtStop",
+                                     committed_error_page_info_->error.reason,
+                                     net::GetAllErrorCodesForUma());
+    UMA_HISTOGRAM_COUNTS("Net.AutoReload.CountAtStop", auto_reload_count_);
+  }
+  if (committed_error_page_info_) {
     committed_error_page_info_->alternate_error_page_url = GURL();
-  if (pending_error_page_info_)
+  }
+  if (pending_error_page_info_) {
     pending_error_page_info_->alternate_error_page_url = GURL();
+  }
   delegate_->CancelFetchErrorPage();
+  auto_reload_timer_->Stop();
+}
+
+void NetErrorHelperCore::OnStop() {
+  CancelPendingFetches();
+  auto_reload_count_ = 0;
+  can_auto_reload_page_ = false;
 }
 
 void NetErrorHelperCore::OnStartLoad(FrameType frame_type, PageType page_type) {
@@ -142,7 +181,13 @@ void NetErrorHelperCore::OnStartLoad(FrameType frame_type, PageType page_type) {
   // If there's no pending error page information associated with the page load,
   // or the new page is not an error page, then reset pending error page state.
   if (!pending_error_page_info_ || page_type != ERROR_PAGE) {
-    OnStop();
+    CancelPendingFetches();
+    // If a non-error load is starting, don't try to auto-reload while it is in
+    // flight.
+    can_auto_reload_page_ = false;
+  } else {
+    // If an error load is starting, the resulting error page is autoreloadable.
+    can_auto_reload_page_ = true;
   }
 }
 
@@ -150,13 +195,32 @@ void NetErrorHelperCore::OnCommitLoad(FrameType frame_type) {
   if (frame_type != MAIN_FRAME)
     return;
 
+  if (committed_error_page_info_ && !pending_error_page_info_ &&
+      can_auto_reload_page_) {
+    int reason = committed_error_page_info_->error.reason;
+    UMA_HISTOGRAM_CUSTOM_ENUMERATION("Net.AutoReload.ErrorAtSuccess",
+                                     reason,
+                                     net::GetAllErrorCodesForUma());
+    UMA_HISTOGRAM_COUNTS("Net.AutoReload.CountAtSuccess", auto_reload_count_);
+    if (auto_reload_count_ == 1) {
+      UMA_HISTOGRAM_CUSTOM_ENUMERATION("Net.AutoReload.ErrorAtFirstSuccess",
+                                       reason,
+                                       net::GetAllErrorCodesForUma());
+    }
+  }
+
   committed_error_page_info_.reset(pending_error_page_info_.release());
 }
 
 void NetErrorHelperCore::OnFinishLoad(FrameType frame_type) {
-  if (frame_type != MAIN_FRAME || !committed_error_page_info_)
+  if (frame_type != MAIN_FRAME)
     return;
 
+  if (!committed_error_page_info_) {
+    auto_reload_count_ = 0;
+    return;
+  }
+
   committed_error_page_info_->is_finished_loading = true;
 
   if (committed_error_page_info_->alternate_error_page_url.is_valid()) {
@@ -167,6 +231,10 @@ void NetErrorHelperCore::OnFinishLoad(FrameType frame_type) {
     GURL error_page_url;
     delegate_->FetchErrorPage(
         committed_error_page_info_->alternate_error_page_url);
+  } else if (auto_reload_enabled_ &&
+             IsReloadableError(*committed_error_page_info_)) {
+    can_auto_reload_page_ = true;
+    MaybeStartAutoReloadTimer();
   }
 
   if (!committed_error_page_info_->needs_dns_updates ||
@@ -317,3 +385,72 @@ blink::WebURLError NetErrorHelperCore::GetUpdatedError(
 
   return updated_error;
 }
+
+void NetErrorHelperCore::Reload() {
+  if (!committed_error_page_info_) {
+    return;
+  }
+  delegate_->ReloadPage();
+}
+
+bool NetErrorHelperCore::MaybeStartAutoReloadTimer() {
+  if (!committed_error_page_info_ || !can_auto_reload_page_)
+    return false;
+
+  DCHECK(IsReloadableError(*committed_error_page_info_));
+
+  if (!online_)
+    return false;
+
+  StartAutoReloadTimer();
+  return true;
+}
+
+void NetErrorHelperCore::StartAutoReloadTimer() {
+  DCHECK(committed_error_page_info_);
+  DCHECK(can_auto_reload_page_);
+  base::TimeDelta delay = GetAutoReloadTime(auto_reload_count_);
+  auto_reload_count_++;
+  auto_reload_timer_->Stop();
+  auto_reload_timer_->Start(FROM_HERE, delay,
+      base::Bind(&NetErrorHelperCore::Reload,
+                 base::Unretained(this)));
+}
+
+void NetErrorHelperCore::NetworkStateChanged(bool online) {
+  online_ = online;
+  if (auto_reload_timer_->IsRunning()) {
+    DCHECK(committed_error_page_info_);
+    // If there's an existing timer running, stop it and reset the retry count.
+    auto_reload_timer_->Stop();
+    auto_reload_count_ = 0;
+  }
+
+  // If the network state changed to online, maybe start auto-reloading again.
+  if (online)
+    MaybeStartAutoReloadTimer();
+}
+
+bool NetErrorHelperCore::ShouldSuppressErrorPage(FrameType frame_type,
+                                                 const GURL& url) {
+  // Don't suppress child frame errors.
+  if (frame_type != MAIN_FRAME)
+    return false;
+
+  // If |auto_reload_timer_| is still running, this error page isn't from an
+  // auto reload.
+  if (auto_reload_timer_->IsRunning())
+    return false;
+
+  // If there's no committed error page, this error page wasn't from an auto
+  // reload.
+  if (!committed_error_page_info_ || !can_auto_reload_page_)
+    return false;
+
+  GURL error_url = committed_error_page_info_->error.unreachableURL;
+  if (error_url != url)
+    return false;
+
+  MaybeStartAutoReloadTimer();
+  return true;
+}