The optional Malware Details also collects HTTP cache information. See design...

chrome/browser/safe_browsing/safe_browsing_service.h

Index: chrome/browser/safe_browsing/safe_browsing_service.h
===================================================================
--- chrome/browser/safe_browsing/safe_browsing_service.h	(revision 76771)
+++ chrome/browser/safe_browsing/safe_browsing_service.h	(working copy)
@@ -233,6 +233,9 @@
   // so the service can serialize and send MalwareDetails.
   virtual void ReportMalwareDetails(scoped_refptr<MalwareDetails> details);
 
+  // When the MalwareDetails is done, OnReportReady is called.

[lzheng, 2011/03/05 00:37:50]

Maybe more explanation on what is "MalwareDetails is done"?

[panayiotis, 2011/03/29 18:14:55]

Done.

+  virtual void OnReportReady(scoped_refptr<MalwareDetails> details);
+
   // Report hits to the unsafe contents (malware, phishing, unsafe download URL)
   // to the server. Can only be called on UI thread.
   void ReportSafeBrowsingHit(const GURL& malicious_url,