Collect some histograms about signed binary downloads.

chrome/browser/safe_browsing/download_protection_service.h

Index: chrome/browser/safe_browsing/download_protection_service.h
===================================================================
--- chrome/browser/safe_browsing/download_protection_service.h	(revision 106761)
+++ chrome/browser/safe_browsing/download_protection_service.h	(working copy)
@@ -32,13 +32,12 @@
 
 // This class provides an asynchronous API to check whether a particular
 // client download is malicious or not.
-class DownloadProtectionService
-    : public base::RefCountedThreadSafe<DownloadProtectionService>,
-      public URLFetcher::Delegate {
+class DownloadProtectionService : public URLFetcher::Delegate {
  public:
-  // TODO(noelutz): we're missing some fields here: filename to get
-  // the signature, server IPs, tab URL redirect chain, ...
+  // TODO(noelutz): we're missing some fields here: server IPs,
+  // tab URL redirect chain, ...
   struct DownloadInfo {
+    FilePath local_file;
     std::vector<GURL> download_url_chain;
     GURL referrer_url;
     std::string sha256_hash;
@@ -65,6 +64,9 @@
       SafeBrowsingService* sb_service,
       net::URLRequestContextGetter* request_context_getter);
 
+  // Note: This class may _only_ be deleted on the IO thread!
+  virtual ~DownloadProtectionService();
+
   // From the URLFetcher::Delegate interface.
   virtual void OnURLFetchComplete(const URLFetcher* source,
                                   const GURL& url,
@@ -107,11 +109,10 @@
     REASON_INVALID_REQUEST_PROTO,
     REASON_SERVER_PING_FAILED,
     REASON_INVALID_RESPONSE_PROTO,
+    REASON_NOT_BINARY_FILE,
     REASON_MAX  // Always add new values before this one.
   };
 
-  virtual ~DownloadProtectionService();
-
  private:
   friend class base::RefCountedThreadSafe<DownloadProtectionService>;
   friend class DownloadProtectionServiceTest;
@@ -124,10 +125,20 @@
 
   static const char kDownloadRequestUrl[];
 
+  // Extracts features from the downloaded file.  Runs in the file thread.
+  // When finished, invokes StartCheckClientDownload on the IO thread.
+  // |pingback_enabled| contains the value of |enabled_| when
+  // CheckClientDownload was called; this is because enabled_ can only be
+  // accessed on the UI thread.
+  void ExtractFileFeatures(const DownloadInfo& info,
+                           bool pingback_enabled,
+                           const CheckDownloadCallback& callback);
+
   // Same as above but this method is called on the IO thread after we have
   // done some basic checks to see whether the download is definitely not
   // safe.
   void StartCheckClientDownload(const DownloadInfo& info,
+                                bool pingback_enabled,
                                 const CheckDownloadCallback& callback);
 
   // This function must run on the UI thread and will invoke the callback
@@ -142,7 +153,8 @@
   void SetEnabledOnIOThread(bool enableed);
 
   // This pointer may be NULL if SafeBrowsing is disabled.
-  scoped_refptr<SafeBrowsingService> sb_service_;
+  // The SafeBrowsingService owns us.
+  SafeBrowsingService* sb_service_;
 
   // The context we use to issue network requests.
   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;