enable download protection on CrOS

chrome/browser/download/notification/download_notification_browsertest.cc

Index: chrome/browser/download/notification/download_notification_browsertest.cc
diff --git a/chrome/browser/download/notification/download_notification_browsertest.cc b/chrome/browser/download/notification/download_notification_browsertest.cc
index 4b72ddafcd3267bea4e296b8e9fd4a2e6d265bc3..24b4b389a58c5de3fb7b27d7e9a2b428121dfb96 100644
--- a/chrome/browser/download/notification/download_notification_browsertest.cc
+++ b/chrome/browser/download/notification/download_notification_browsertest.cc
@@ -230,6 +230,13 @@ class TestChromeDownloadManagerDelegate : public ChromeDownloadManagerDelegate {
   // Return if  the download is opened.
   bool opened() const { return opened_; }
 
+ protected:
+  // Disable DownloadProtectionService in order to disable content checking.
+  safe_browsing::DownloadProtectionService* GetDownloadProtectionService()
+      override {
+    return NULL;

[asanka, 2015/10/21 13:53:21]

Nit: nullptr instead of NULL.

[Jialiu Lin, 2015/10/21 20:14:55]

Done.

+  }
+
  private:
   bool opened_;
 };