[Sync] Store the past 10 traffic records in memory.

sync/sessions/sync_session_context.h

Index: sync/sessions/sync_session_context.h
diff --git a/sync/sessions/sync_session_context.h b/sync/sessions/sync_session_context.h
index 94129ce9cee033d9b0815e1056b514852f9ece22..cae7f1c2d445a9e78734a731a3a536ee9e52b6af 100644
--- a/sync/sessions/sync_session_context.h
+++ b/sync/sessions/sync_session_context.h
@@ -27,6 +27,7 @@
 #include "base/time.h"
 #include "sync/engine/model_safe_worker.h"
 #include "sync/engine/syncer_types.h"
+#include "sync/engine/traffic_recorder.h"
 #include "sync/sessions/debug_info_getter.h"
 
 namespace syncable {
@@ -123,6 +124,10 @@ class SyncSessionContext {
   // new throttled types this will remain constant through out the sync cycle.
   syncable::ModelTypeSet GetThrottledTypes() const;
 
+  browser_sync::TrafficRecorder* traffic_recorder() {
+    return &traffic_recorder_;
+  }
+
  private:
   typedef std::map<syncable::ModelType, base::TimeTicks> UnthrottleTimes;
 
@@ -177,6 +182,8 @@ class SyncSessionContext {
   // unthrottled.
   UnthrottleTimes unthrottle_times_;
 
+  browser_sync::TrafficRecorder traffic_recorder_;

[tim (not reviewing), 2012/03/29 22:02:23]

Please see my comment on http://codereview.chromium.org/9826035/.  I think we
should follow the pattern here and have this object live at the top of the stack
of where it is used (in SyncManager) to avoid circuitous accesses of the context
from (e.g. the scheduler).

[lipalani1, 2012/03/30 00:33:24]

Tim - this is fixed in the next patch. In this patch it is not used elsewhere
and scheduler does not expose it either. So no layering violations.
I have left a todo here which will be fixed in the next patch. Hope that is OK.

On 2012/03/29 22:02:23, timsteele wrote:

+
   DISALLOW_COPY_AND_ASSIGN(SyncSessionContext);
 };