Include all server redirects in referrer chain

chrome/common/safe_browsing/csd.proto

Index: chrome/common/safe_browsing/csd.proto
diff --git a/chrome/common/safe_browsing/csd.proto b/chrome/common/safe_browsing/csd.proto
index c98152aae1a51efa35eeddf5e3f7a75f5d311e0b..53a64af194c79b7aa1f96b3c6d5363d3fff0e36d 100644
--- a/chrome/common/safe_browsing/csd.proto
+++ b/chrome/common/safe_browsing/csd.proto
@@ -416,6 +416,11 @@ message ReferrerChainEntry {
   optional bool is_retargeting = 6;
 
   optional double navigation_time_msec = 7;
+
+  // Set only if server redirects happen in navigation.
+  // The first entry in |server_redirect_chain| should be the original request

[Nathan Parker, 2017/01/20 23:36:20]

Looks like the last entry would be redundant, but if auk et.al would prefer it
that way, fine with me.

[Jialiu Lin, 2017/01/21 00:48:27]

I think it is less confusing in this way. auk and others didn't object when I
made change in the csd_client.proto. 

+  // url, and the last entry should be the same as |url|.
+  repeated string server_redirect_chain = 8;
 }  // End of URLChainEntry
 
 message ClientDownloadResponse {