Refactor BaseBlockingPage to reduce duplicated code

chrome/browser/safe_browsing/ui_manager_unittest.cc

Index: chrome/browser/safe_browsing/ui_manager_unittest.cc
diff --git a/chrome/browser/safe_browsing/ui_manager_unittest.cc b/chrome/browser/safe_browsing/ui_manager_unittest.cc
index b652b9153537835b3b2c9b5ee39ded598cc63d8c..744c2aaff3da1d85bd4b4d4b2de117bd252f8581 100644
--- a/chrome/browser/safe_browsing/ui_manager_unittest.cc
+++ b/chrome/browser/safe_browsing/ui_manager_unittest.cc
@@ -352,7 +352,7 @@ class TestSafeBrowsingBlockingPage : public SafeBrowsingBlockingPage {
                 false,
                 false)) {
     // Don't delay details at all for the unittest.
-    threat_details_proceed_delay_ms_ = 0;
+    SetThreatDetailsProceedDelayForTesting(0);
     DontCreateViewForTesting();
   }
 };