Set up Finch trial for malware download warnings

chrome/browser/resources/downloads/downloads.js

Index: chrome/browser/resources/downloads/downloads.js
diff --git a/chrome/browser/resources/downloads/downloads.js b/chrome/browser/resources/downloads/downloads.js
index c6a625311b8ef2f58a5b357a572366204006a7a1..0979d0cdf10ea9600fdc74cdb54e1a8ef0eee753 100644
--- a/chrome/browser/resources/downloads/downloads.js
+++ b/chrome/browser/resources/downloads/downloads.js
@@ -423,6 +423,7 @@ Download.prototype.update = function(download) {
   this.state_ = download.state;
   this.fileExternallyRemoved_ = download.file_externally_removed;
   this.dangerType_ = download.danger_type;
+  this.finchString_ = download.finch_string;
   this.lastReasonDescription_ = download.last_reason_text;
   this.byExtensionId_ = download.by_ext_id;
   this.byExtensionName_ = download.by_ext_name;
@@ -452,6 +453,10 @@ Download.prototype.update = function(download) {
       this.dangerDesc_.textContent = loadTimeData.getStringF(
           'danger_potentially_unwanted_desc', this.fileName_);
     }
+    if (this.finchString_) {
+      // Finch trial overrides the normal display string.
+      this.dangerDesc_.textContent = this.finchString_;
+    }
     this.danger_.style.display = 'block';
     this.safe_.style.display = 'none';
   } else {