Move download attribution right after CheckDownloadUrl

chrome/browser/safe_browsing/download_protection_service.h

Index: chrome/browser/safe_browsing/download_protection_service.h
diff --git a/chrome/browser/safe_browsing/download_protection_service.h b/chrome/browser/safe_browsing/download_protection_service.h
index e7fee05b4c4adbc2ede1f1289518485c6a5fafc4..c0ff4b7ba4171b97fc42cf6c78d6994d079b3a2c 100644
--- a/chrome/browser/safe_browsing/download_protection_service.h
+++ b/chrome/browser/safe_browsing/download_protection_service.h
@@ -118,7 +118,7 @@ class DownloadProtectionService {
   // delivered asynchronously via the given callback.  This method must be
   // called on the UI thread, and the callback will also be invoked on the UI
   // thread.  Pre-condition: !info.download_url_chain.empty().
-  virtual void CheckDownloadUrl(const content::DownloadItem& item,
+  virtual void CheckDownloadUrl(content::DownloadItem* item,
                                 const CheckDownloadCallback& callback);
 
   // Returns true iff the download specified by |info| should be scanned by
@@ -223,6 +223,7 @@ class DownloadProtectionService {
  private:
   class CheckClientDownloadRequest;
   class PPAPIDownloadRequest;
+  friend class DownloadSBClient;
   friend class DownloadProtectionServiceTest;
   friend class DownloadDangerPromptTest;
 
@@ -259,6 +260,8 @@ class DownloadProtectionService {
 
   static const void* const kDownloadPingTokenKey;
 
+  static const void* const kDownloadReferrerChainDataKey;

[Nathan Parker, 2017/01/24 22:46:46]

nit: could this be in a anonymous namespace in the .cc file instead?  This and
the others here.  If they're used in tests, then never mind.

[Jialiu Lin, 2017/01/25 00:11:20]

Done.
kDownloadPingTokenKey is used in a browser test. 
So I only put kDownloadReferrerChainDataKey in the anonymous namespace.

+
   // Helper class for easy setting and getting token string.
   class DownloadPingToken : public base::SupportsUserData::Data {
    public:
@@ -295,13 +298,13 @@ class DownloadProtectionService {
   // Returns the URL that will be used for download requests.
   static GURL GetDownloadRequestUrl();
 
-  // If kDownloadAttribution feature is enabled, identify and add referrer chain
-  // info of a download to ClientDownloadRequest proto. This function also
-  // records UMA stats of download attribution result.
-  void AddReferrerChainToClientDownloadRequest(
+  // If kDownloadAttribution feature is enabled, identify referrer chain info of
+  // a download. This function also records UMA stats of download attribution
+  // result.
+  void IdentifyReferrerChain(
     const GURL& download_url,
     content::WebContents* web_contents,
-    ClientDownloadRequest* out_request);
+    ReferrerChain* out_referrer_chain);
 
   // If kDownloadAttribution feature is enabled, identify referrer chain of the
   // PPAPI download based on the frame URL where the download is initiated.