Redirect handling in the resource_prefetch_predictor.

chrome/browser/predictors/resource_prefetch_predictor.proto

Index: chrome/browser/predictors/resource_prefetch_predictor.proto
diff --git a/chrome/browser/predictors/resource_prefetch_predictor.proto b/chrome/browser/predictors/resource_prefetch_predictor.proto
index 8616d5c71c5c01910d63100cc9b02ef6007bd206..cf0b7f45e49fad9dc85776048900c9dc50b4dad8 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor.proto
+++ b/chrome/browser/predictors/resource_prefetch_predictor.proto
@@ -4,11 +4,11 @@
 
 // Protocol buffers used for storing in SQLite.
 // CAUTION: When any change is done here, bump kDatabaseVersion in
-//          resource_prefetch_predictor.h.
+//          resource_prefetch_predictor_tables.h.
 
 syntax = "proto2";
 
-package chrome_browser_predictors;
+package predictors;
 
 // Required in Chrome.
 option optimize_for = LITE_RUNTIME;
@@ -61,3 +61,18 @@ message ResourceData {
   optional bool has_validators = 8;
   optional bool always_revalidate = 9;
 }
+
+// Represents a mapping of origin to all possible endpoints.

[pasko, 2016/09/27 16:21:27]

hm, this is again confusing because a web origin is a different thing.

See: https://tools.ietf.org/html/rfc6454

I think I suggested to call it an origin because I thought we'd do it sooner,
but we decided to postpone it. Sorry. Let's say something like:
// Represents a mapping from URL or host to a list of redirect endpoints.

note: removed 'all' because we actually clean the ones that have too many misses

[alexilin, 2016/09/27 18:11:08]

Done.

+message RedirectData {
+  // Represents a single redirect chain endpoint.
+  message RedirectStat {
+    optional string url = 1;

[pasko, 2016/09/27 16:21:27]

needs a comment like:
// For RedirectData in a host-based table |url| represents the host.

[alexilin, 2016/09/27 18:11:08]

Done.

+    optional uint32 number_of_hits = 2;
+    optional uint32 number_of_misses = 3;
+    optional uint32 consecutive_misses = 4;
+  }
+
+  optional string primary_key = 1;

[pasko, 2016/09/27 16:21:27]

needs a comment like:
// Main frame URL or host.

[alexilin, 2016/09/27 18:11:08]

Done.

+  optional uint64 last_visit_time = 2;
+  repeated RedirectStat redirect_endpoints = 3;
+}