Make the throttle delay configurable by the server.

BUG=
TEST=


Review URL: http://codereview.chromium.org/7605021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@96312 0039d316-1c4b-4281-b951-d872f2087c98

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 +183,20 @@ bool SyncerProtoUtil::PostAndProcessHeaders(ServerConnectionManager* scm,
   return false;
 }
 
+base::TimeDelta SyncerProtoUtil::GetThrottleDelay(
+    const sync_pb::ClientToServerResponse& response) {
+  base::TimeDelta throttle_delay =
+      base::TimeDelta::FromSeconds(kSyncDelayAfterThrottled);
+  if (response.has_client_command()) {
+    const sync_pb::ClientCommand& command = response.client_command();
+    if (command.has_throttle_delay_seconds()) {
+      throttle_delay =
+          base::TimeDelta::FromSeconds(command.throttle_delay_seconds());
+    }
+  }
+  return throttle_delay;
+}
+
 namespace {
 
 // Helper function for an assertion in PostClientToServerMessage.
@@ -236,7 +251,7 @@ 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;

chrome/browser/sync/engine/syncer_proto_util.h

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -115,6 +115,9 @@ class SyncerProtoUtil {
                                     const ClientToServerMessage& msg,
                                     sync_pb::ClientToServerResponse* response);
 
+  static base::TimeDelta GetThrottleDelay(
+      const sync_pb::ClientToServerResponse& response);
+
   friend class SyncerProtoUtilTest;
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, AddRequestBirthday);
   FRIEND_TEST_ALL_PREFIXES(SyncerProtoUtilTest, PostAndProcessHeaders);

chrome/browser/sync/protocol/sync.proto

@@ -586,6 +586,9 @@ message ClientCommand {
   // action and sending a commit message to the
   // server
   optional int32 sessions_commit_delay_seconds = 4;
+
+  // Number of seconds to delay before the throttled client should retry.
+  optional int32 throttle_delay_seconds = 5;
 };
 
 message ClientToServerResponse {