Set up Finch trial for malware download warnings

chrome/browser/download/download_item_model.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/download/download_item_model.h"
 
 #include "base/i18n/number_formatting.h"
 #include "base/i18n/rtl.h"
+#include "base/metrics/field_trial.h"
 #include "base/strings/string16.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/supports_user_data.h"
 #include "base/time/time.h"
 #include "chrome/browser/download/download_crx_util.h"
+#include "chrome/browser/download/download_util.h"
 #include "chrome/browser/safe_browsing/download_feedback_service.h"
 #include "content/public/browser/download_danger_type.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_item.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/time_format.h"
 #include "ui/base/text/bytes_formatting.h"
 #include "ui/base/text/text_elider.h"
@@ skipping 269 matching lines @@
     tooltip += ui::ElideText(InterruptReasonStatusMessage(reason),
                              font, max_width, ui::ELIDE_AT_END);
   }
   return tooltip;
 }
 
 string16 DownloadItemModel::GetWarningText(const gfx::Font& font,
                                            int base_width) const {
   // Should only be called if IsDangerous().
   DCHECK(IsDangerous());
+  std::string trial_condition =
+      base::FieldTrialList::FindFullName(download_util::kFinchTrialName);
   string16 elided_filename =
       ui::ElideFilename(download_->GetFileNameToReportUser(), font, base_width);
   switch (download_->GetDangerType()) {
     case content::DOWNLOAD_DANGER_TYPE_DANGEROUS_URL:
-      return l10n_util::GetStringUTF16(IDS_PROMPT_MALICIOUS_DOWNLOAD_URL);
-
+      if (trial_condition.empty()) {
+        return l10n_util::GetStringUTF16(IDS_PROMPT_MALICIOUS_DOWNLOAD_URL);
+      } else {
+        return download_util::AssembleMalwareFinchString(trial_condition,
+                                                         elided_filename);
+      }
     case content::DOWNLOAD_DANGER_TYPE_DANGEROUS_FILE:
       if (download_crx_util::IsExtensionDownload(*download_)) {
         return l10n_util::GetStringUTF16(
             IDS_PROMPT_DANGEROUS_DOWNLOAD_EXTENSION);
       } else {
         return l10n_util::GetStringFUTF16(IDS_PROMPT_DANGEROUS_DOWNLOAD,
                                           elided_filename);
       }
-
     case content::DOWNLOAD_DANGER_TYPE_DANGEROUS_CONTENT:
     case content::DOWNLOAD_DANGER_TYPE_DANGEROUS_HOST:
-      return l10n_util::GetStringFUTF16(IDS_PROMPT_MALICIOUS_DOWNLOAD_CONTENT,
-                                        elided_filename);
-
+      if (trial_condition.empty()) {
+        return l10n_util::GetStringFUTF16(IDS_PROMPT_MALICIOUS_DOWNLOAD_CONTENT,
+                                          elided_filename);
+      } else {
+        return download_util::AssembleMalwareFinchString(trial_condition,
+                                                         elided_filename);
+      }
     case content::DOWNLOAD_DANGER_TYPE_UNCOMMON_CONTENT:
       return l10n_util::GetStringFUTF16(IDS_PROMPT_UNCOMMON_DOWNLOAD_CONTENT,
                                         elided_filename);
 
     case content::DOWNLOAD_DANGER_TYPE_POTENTIALLY_UNWANTED:
       return l10n_util::GetStringFUTF16(
           IDS_PROMPT_DOWNLOAD_CHANGES_SEARCH_SETTINGS, elided_filename);
 
     case content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS:
     case content::DOWNLOAD_DANGER_TYPE_MAYBE_DANGEROUS_CONTENT:
@@ skipping 196 matching lines @@
   }
 
   // In progress download with no known time left and non-zero completed bytes:
   // "100/120 MB" or "100 MB"
   if (GetCompletedBytes() > 0)
     return size_ratio;
 
   // Instead of displaying "0 B" we say "Starting..."
   return l10n_util::GetStringUTF16(IDS_DOWNLOAD_STATUS_STARTING);
 }