Add timestamp to infobar for stale Previews

Add a feature to enable a timestamp on the Previews infobar. This
timestamp should be shown when the previews_freshness is greater
than the finch controlled "min_staleness_in_minutes" and less than
"max_staleness_in_minutes".

BUG=718643

Review-Url: https://codereview.chromium.org/2940083003
Cr-Commit-Position: refs/heads/master@{#481018}

chrome/app/generated_resources.grd

@@ -4975,6 +4975,15 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_PREVIEWS_INFOBAR_LINK" desc="The text of the link to load the original page from the infobar notifying the user that a preview page has been shown.">
          Show original
       </message>
+      <message name="IDS_PREVIEWS_INFOBAR_TIMESTAMP_MINUTES" desc="The desciption stating how old a preview version of a page is in minutes. This is shown on the infobar notifying the user that a preview page has been shown.">
+         Updated <ph name="MINUTES">$1<ex>30</ex></ph>min ago
+      </message>
+      <message name="IDS_PREVIEWS_INFOBAR_TIMESTAMP_ONE_HOUR" desc="The desciption stating a preview version of a page is one hour old. This is shown on the infobar notifying the user that a preview page has been shown.">
+         Updated 1hr ago
+      </message>
+      <message name="IDS_PREVIEWS_INFOBAR_TIMESTAMP_HOURS" desc="The desciption stating how old a preview version of a page is in hours. This is shown on the infobar notifying the user that a preview page has been shown.">
+         Updated <ph name="HOURS">$1<ex>4</ex></ph>hrs ago
+      </message>
 
       <!-- WebRTC logs -->
       <message name="IDS_WEBRTC_LOGS_TITLE" desc="Title for the chrome://webrtc-logs page.">

chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_io_data.cc

@@ -60,7 +60,8 @@ void AddPreviewNavigationToBlackListCallback(
 void OnLoFiResponseReceivedOnUI(content::WebContents* web_contents) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   PreviewsInfoBarDelegate::Create(
-      web_contents, previews::PreviewsType::LOFI, true /* is_data_saver_user */,
+      web_contents, previews::PreviewsType::LOFI,
+      base::Time() /* previews_freshness */, true /* is_data_saver_user */,
       base::Bind(&AddPreviewNavigationToBlackListCallback,
                  web_contents->GetBrowserContext(),
                  web_contents->GetController()

chrome/browser/previews/previews_infobar_delegate.cc

@@ -4,9 +4,15 @@
 
 #include "chrome/browser/previews/previews_infobar_delegate.h"
 
+#include "base/feature_list.h"
+#include "base/metrics/field_trial_params.h"
 #include "base/metrics/histogram.h"
 #include "base/optional.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/android/android_theme_resources.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/infobars/infobar_service.h"
 #include "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h"
 #include "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings_factory.h"
@@ -16,6 +22,8 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_service.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "components/infobars/core/infobar.h"
+#include "components/network_time/network_time_tracker.h"
+#include "components/previews/core/previews_features.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -101,6 +109,7 @@ PreviewsInfoBarDelegate::~PreviewsInfoBarDelegate() {
 void PreviewsInfoBarDelegate::Create(
     content::WebContents* web_contents,
     previews::PreviewsType previews_type,
+    base::Time previews_freshness,
     bool is_data_saver_user,
     const OnDismissPreviewsInfobarCallback& on_dismiss_callback) {
   PreviewsInfoBarTabHelper* infobar_tab_helper =
@@ -116,7 +125,8 @@ void PreviewsInfoBarDelegate::Create(
     return;
 
   std::unique_ptr<PreviewsInfoBarDelegate> delegate(new PreviewsInfoBarDelegate(
-      web_contents, previews_type, is_data_saver_user, on_dismiss_callback));
+      web_contents, previews_type, previews_freshness, is_data_saver_user,
+      on_dismiss_callback));
 
 #if defined(OS_ANDROID)
   std::unique_ptr<infobars::InfoBar> infobar_ptr(
@@ -144,10 +154,12 @@ void PreviewsInfoBarDelegate::Create(
 PreviewsInfoBarDelegate::PreviewsInfoBarDelegate(
     content::WebContents* web_contents,
     previews::PreviewsType previews_type,
+    base::Time previews_freshness,
     bool is_data_saver_user,
     const OnDismissPreviewsInfobarCallback& on_dismiss_callback)
     : ConfirmInfoBarDelegate(),
       previews_type_(previews_type),
+      previews_freshness_(previews_freshness),
       infobar_dismissed_action_(INFOBAR_DISMISSED_BY_TAB_CLOSURE),
       message_text_(l10n_util::GetStringUTF16(
           is_data_saver_user ? IDS_PREVIEWS_INFOBAR_SAVED_DATA_TITLE
@@ -180,7 +192,18 @@ void PreviewsInfoBarDelegate::InfoBarDismissed() {
 }
 
 base::string16 PreviewsInfoBarDelegate::GetMessageText() const {
+// Android has a custom infobar that calls GetTimestampText() and adds the
+// timestamp in a separate description view. Other OS's can enable previews
+// for debugging purposes and don't have a custom infobar with a description
+// view, so the timestamp should be appended to the message.
+#if defined(OS_ANDROID)
   return message_text_;
+#else
+  base::string16 timestamp = GetTimestampText();
+  if (timestamp.empty())
+    return message_text_;
+  return message_text_ + base::ASCIIToUTF16(" ") + timestamp;
+#endif
 }
 
 int PreviewsInfoBarDelegate::GetButtons() const {
@@ -214,5 +237,48 @@ bool PreviewsInfoBarDelegate::LinkClicked(WindowOpenDisposition disposition) {
 }
 
 base::string16 PreviewsInfoBarDelegate::GetTimestampText() const {
-  return base::string16();
+  if (previews_freshness_.is_null())
+    return base::string16();
+  if (!base::FeatureList::IsEnabled(
+          previews::features::kStalePreviewsTimestamp)) {
+    return base::string16();
+  }
+
+  int min_staleness_in_minutes = base::GetFieldTrialParamByFeatureAsInt(
+      previews::features::kStalePreviewsTimestamp, "min_staleness_in_minutes",
+      0);
+  int max_staleness_in_minutes = base::GetFieldTrialParamByFeatureAsInt(
+      previews::features::kStalePreviewsTimestamp, "max_staleness_in_minutes",
+      0);
+
+  if (min_staleness_in_minutes == 0 || max_staleness_in_minutes == 0)
+    return base::string16();
+
+  base::Time network_time;
+  if (g_browser_process->network_time_tracker()->GetNetworkTime(&network_time,
+                                                                nullptr) !=
+      network_time::NetworkTimeTracker::NETWORK_TIME_AVAILABLE) {
+    // When network time has not been initialized yet, simply rely on the
+    // machine's current time.
+    network_time = base::Time::Now();
+  }
+
+  int staleness_in_minutes = (network_time - previews_freshness_).InMinutes();
+  // TODO(megjablon): record metrics for out of bounds staleness.
+  if (staleness_in_minutes < min_staleness_in_minutes)
+    return base::string16();
+  if (staleness_in_minutes > max_staleness_in_minutes)
+    return base::string16();
+
+  if (staleness_in_minutes < 60) {
+    return l10n_util::GetStringFUTF16(
+        IDS_PREVIEWS_INFOBAR_TIMESTAMP_MINUTES,
+        base::IntToString16(staleness_in_minutes));
+  } else if (staleness_in_minutes < 120) {
+    return l10n_util::GetStringUTF16(IDS_PREVIEWS_INFOBAR_TIMESTAMP_ONE_HOUR);
+  } else {
+    return l10n_util::GetStringFUTF16(
+        IDS_PREVIEWS_INFOBAR_TIMESTAMP_HOURS,
+        base::IntToString16(staleness_in_minutes / 60));
+  }
 }

chrome/browser/previews/previews_infobar_delegate.h

@@ -7,6 +7,7 @@
 
 #include "base/callback.h"
 #include "base/strings/string16.h"
+#include "base/time/time.h"
 #include "components/infobars/core/confirm_infobar_delegate.h"
 #include "components/previews/core/previews_experiments.h"
 
@@ -41,10 +42,12 @@ class PreviewsInfoBarDelegate : public ConfirmInfoBarDelegate {
   static void Create(
       content::WebContents* web_contents,
       previews::PreviewsType previews_type,
+      base::Time previews_freshness,
       bool is_data_saver_user,
       const OnDismissPreviewsInfobarCallback& on_dismiss_callback);
 
   // ConfirmInfoBarDelegate overrides:
+  int GetIconId() const override;
   base::string16 GetMessageText() const override;
   base::string16 GetLinkText() const override;
 
@@ -54,18 +57,21 @@ class PreviewsInfoBarDelegate : public ConfirmInfoBarDelegate {
   PreviewsInfoBarDelegate(
       content::WebContents* web_contents,
       previews::PreviewsType previews_type,
+      base::Time previews_freshness,
       bool is_data_saver_user,
       const OnDismissPreviewsInfobarCallback& on_dismiss_callback);
 
   // ConfirmInfoBarDelegate overrides:
   infobars::InfoBarDelegate::InfoBarIdentifier GetIdentifier() const override;
-  int GetIconId() const override;
   bool ShouldExpire(const NavigationDetails& details) const override;
   void InfoBarDismissed() override;
   int GetButtons() const override;
   bool LinkClicked(WindowOpenDisposition disposition) override;
 
   previews::PreviewsType previews_type_;
+  // The time at which the preview associated with this infobar was created. A
+  // value of zero means that the creation time is unknown.
+  const base::Time previews_freshness_;
   mutable PreviewsInfoBarAction infobar_dismissed_action_;
 
   const base::string16 message_text_;

chrome/browser/previews/previews_infobar_tab_helper.cc

@@ -105,6 +105,7 @@ void PreviewsInfoBarTabHelper::DidFinishNavigation(
                 web_contents()->GetBrowserContext());
     PreviewsInfoBarDelegate::Create(
         web_contents(), previews::PreviewsType::OFFLINE,
+        base::Time() /* previews_freshness */,
         data_reduction_proxy_settings &&
             data_reduction_proxy_settings->IsDataReductionProxyEnabled(),
         base::Bind(&AddPreviewNavigationCallback, browser_context_,
@@ -118,8 +119,10 @@ void PreviewsInfoBarTabHelper::DidFinishNavigation(
   const net::HttpResponseHeaders* headers =
       navigation_handle->GetResponseHeaders();
   if (headers && data_reduction_proxy::IsLitePagePreview(*headers)) {
+    base::Time previews_freshness;
+    headers->GetDateValue(&previews_freshness);
     PreviewsInfoBarDelegate::Create(
-        web_contents(), previews::PreviewsType::LITE_PAGE,
+        web_contents(), previews::PreviewsType::LITE_PAGE, previews_freshness,
         true /* is_data_saver_user */,
         base::Bind(&AddPreviewNavigationCallback, browser_context_,
                    navigation_handle->GetRedirectChain()[0],

components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc

@@ -11,6 +11,7 @@
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_protocol.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_compression_stats.h"

components/previews/core/previews_features.cc

@@ -15,5 +15,9 @@ const base::Feature kOfflinePreviews{"OfflinePreviews",
 const base::Feature kClientLoFi{"ClientLoFi",
                                 base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Enables the Stale Previews timestamp on Previews infobars.
+const base::Feature kStalePreviewsTimestamp{"StalePreviewsTimestamp",
+                                            base::FEATURE_DISABLED_BY_DEFAULT};
+
 }  // namespace features
 }  // namespace previews

components/previews/core/previews_features.h

@@ -12,6 +12,7 @@ namespace features {
 
 extern const base::Feature kOfflinePreviews;
 extern const base::Feature kClientLoFi;
+extern const base::Feature kStalePreviewsTimestamp;
 
 }  // namespace features
 }  // namespace previews