Three way experiment for "Show saved copy" button.

chrome/common/localized_error.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/common/localized_error.h"
 
+#include "base/command_line.h"
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/error_page/common/error_page_params.h"
 #include "components/error_page/common/net_error_info.h"
 #include "net/base/escape.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
 #include "third_party/WebKit/public/platform/WebURLError.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/webui/web_ui_util.h"
@@ skipping 477 matching lines @@
 }
 
 }  // namespace
 
 const char LocalizedError::kHttpErrorDomain[] = "http";
 
 void LocalizedError::GetStrings(int error_code,
                                 const std::string& error_domain,
                                 const GURL& failed_url,
                                 bool is_post,
-                                bool show_stale_load_button,
+                                bool stale_copy_in_cache,
                                 const std::string& locale,
                                 const std::string& accept_languages,
                                 scoped_ptr<error_page::ErrorPageParams> params,
                                 base::DictionaryValue* error_strings) {
   webui::SetLoadTimeDataDefaults(locale, error_strings);
 
   // Grab the strings and settings that depend on the error type.  Init
   // options with default values.
   LocalizedErrorMap options = {
     0,
@@ skipping 159 matching lines @@
       // Add at the front, so it appears before other suggestions, in the case
       // suggestions are being overridden by |params|.
       suggestions->Insert(0, suggest_reload_repost);
     }
   }
 
   // If not using the default suggestions, nothing else to do.
   if (!use_default_suggestions)
     return;
 
-  if (show_stale_load_button) {
-    base::DictionaryValue* stale_load_button = new base::DictionaryValue;
-    stale_load_button->SetString(
-        "msg", l10n_util::GetStringUTF16(IDS_ERRORPAGES_BUTTON_LOAD_STALE));
-    stale_load_button->SetString(
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  const std::string& show_saved_copy_value =
+      command_line->GetSwitchValueASCII(switches::kShowSavedCopy);
+  bool show_saved_copy_primary = (show_saved_copy_value ==
+      switches::kEnableShowSavedCopyPrimary);
+  bool show_saved_copy_visible =
+      (stale_copy_in_cache && !is_post &&
+      (show_saved_copy_primary ||
+          show_saved_copy_value == switches::kEnableShowSavedCopySecondary));

[Lei Zhang, 2015/03/02 20:31:03]

nit: I would just create a |show_saved_copy_secondary| variable so this
assignment logic is a bit more readable.

[megjablon, 2015/03/03 01:07:38]

Done.

+
+  if (show_saved_copy_visible) {
+    base::DictionaryValue* show_saved_copy_button = new base::DictionaryValue;
+    show_saved_copy_button->SetString(
+        "msg", l10n_util::GetStringUTF16(
+            IDS_ERRORPAGES_BUTTON_SHOW_SAVED_COPY));
+    show_saved_copy_button->SetString(
         "title",
-        l10n_util::GetStringUTF16(IDS_ERRORPAGES_BUTTON_LOAD_STALE_HELP));
-    error_strings->Set("staleLoadButton", stale_load_button);
+        l10n_util::GetStringUTF16(IDS_ERRORPAGES_BUTTON_SHOW_SAVED_COPY_HELP));
+    if (show_saved_copy_primary)
+      show_saved_copy_button->SetString("primary", "true");
+    error_strings->Set("showSavedCopyButton", show_saved_copy_button);
   }
 
 #if defined(OS_CHROMEOS)
   error_strings->SetString(
       "diagnose", l10n_util::GetStringUTF16(IDS_ERRORPAGES_BUTTON_DIAGNOSE));
 #endif  // defined(OS_CHROMEOS)
 
   if (options.suggestions & SUGGEST_CHECK_CONNECTION) {
     base::DictionaryValue* suggest_check_connection = new base::DictionaryValue;
     suggest_check_connection->SetString("header",
@@ skipping 171 matching lines @@
   GURL learn_more_url(kAppWarningLearnMoreUrl);
   base::DictionaryValue* suggest_learn_more = new base::DictionaryValue();
   suggest_learn_more->SetString("msg",
                                 l10n_util::GetStringUTF16(
                                     IDS_ERRORPAGES_SUGGESTION_LEARNMORE_BODY));
   suggest_learn_more->SetString("learnMoreUrl", learn_more_url.spec());
   error_strings->Set("suggestionsLearnMore", suggest_learn_more);
 #endif  // defined(OS_CHROMEOS)
 }
 #endif