Make the throttle delay configurable by the server.

chrome/browser/sync/engine/syncer_proto_util.cc

Index: chrome/browser/sync/engine/syncer_proto_util.cc
diff --git a/chrome/browser/sync/engine/syncer_proto_util.cc b/chrome/browser/sync/engine/syncer_proto_util.cc
index 6dae7689f12e54886bdb2e3844ff305f598fc48b..87eae4efe836043172d05cee6508ebfa38bccad0 100644
--- a/chrome/browser/sync/engine/syncer_proto_util.cc
+++ b/chrome/browser/sync/engine/syncer_proto_util.cc
@@ -11,6 +11,7 @@
 #include "chrome/browser/sync/engine/syncer_types.h"
 #include "chrome/browser/sync/engine/syncer_util.h"
 #include "chrome/browser/sync/protocol/service_constants.h"
+#include "chrome/browser/sync/protocol/sync.pb.h"
 #include "chrome/browser/sync/sessions/sync_session.h"
 #include "chrome/browser/sync/syncable/directory_manager.h"
 #include "chrome/browser/sync/syncable/model_type.h"
@@ -182,6 +183,17 @@ bool SyncerProtoUtil::PostAndProcessHeaders(ServerConnectionManager* scm,
   return false;
 }
 
+base::TimeDelta SyncerProtoUtil::GetThrottleDelay(
+    const sync_pb::ClientToServerResponse& response) {
+  if (!response.has_client_command())
+    return base::TimeDelta::FromSeconds(kSyncDelayAfterThrottled);
+  const sync_pb::ClientCommand& command = response.client_command();
+  if (command.has_throttle_delay_seconds())
+    return base::TimeDelta::FromSeconds(command.throttle_delay_seconds());
+  else
+    return base::TimeDelta::FromSeconds(kSyncDelayAfterThrottled);

[akalin, 2011/08/10 19:48:14]

i don't like repeating the constant twice.  How about using:

base::TimeDelta throttle_delay =
    base::TimeDelta::FromSeconds(kSyncDelayAfterThrottled);
if (response.has_client_command()) {
  const ...;
  if (command.has_throttle_delay_seconds()) {
    throttle_delay = base...;
  }
}
return throttle_delay;

or

base::TimeDelta default_throttle_delay =
    base::TimeDelta::FromSeconds(kSyncDelayAfterThrottled);
if (!response.has_client_command()) {
  return default_throttle_delay;
}
const ...;
if (!command.has_throttle_delay_seconds()) {
  return default_throttle_delay;
}
return FromSeconds(command.throttle_delay_seconds());

[lipalani1, 2011/08/10 20:38:58]

Done.

+}
+
 namespace {
 
 // Helper function for an assertion in PostClientToServerMessage.
@@ -236,7 +248,7 @@ bool SyncerProtoUtil::PostClientToServerMessage(
     case ClientToServerResponse::THROTTLED:
       LOG(WARNING) << "Client silenced by server.";
       session->delegate()->OnSilencedUntil(base::TimeTicks::Now() +
-          base::TimeDelta::FromSeconds(kSyncDelayAfterThrottled));
+          GetThrottleDelay(*response));
       return false;
     case ClientToServerResponse::TRANSIENT_ERROR:
       return false;