Add timeout to clearing server data

Background: the sync nudge infrastructure is highly tuned for sync scenarios -- a fire-and-forget nudge is sent tothe sync thread which kicks off sync.  If the syncer is disconnected, throttled, paused, etc, then the nudge is dropped as a sync cannot happen.

Problem: one-shot commands such as clearing server data can also be dropped without any acknowledgment, which means that the UI is never updated.  There were a few alternatives for fixing this: 1) threading the clear through, 2) adding a timeout, or 3) fixing the nudge infrastructure to support more reliable messaging semantics.  #3 was the ideal choice, however not doable for M8.  Until the syncer is redesigned, #2 is our stop-gap solution.

On success, sync is disabled and the dialog dialog is closed.  We do not care if a timeout event occurred thereafter, and theres no reason to show an error message to the user at that point.  A similar situation exists if you are looking at the dialog and someone clears from another browser: the dialog closes itself without warning and without regard to any local requests to clear.

BUG=57360
TEST=

Review URL: http://codereview.chromium.org/3720001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@62424 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 31 insertions, 4 deletions

diff --git a/chrome/browser/sync/profile_sync_service.cc b/chrome/browser/sync/profile_sync_service.cc
index 276ad22..41069c8 100644
--- a/chrome/browser/sync/profile_sync_service.cc
+++ b/chrome/browser/sync/profile_sync_service.cc
@@ -56,6 +56,8 @@ const char* ProfileSyncService::kSyncServerUrl =
 const char* ProfileSyncService::kDevServerUrl =
     "https://clients4.google.com/chrome-sync/dev";
 
+static const int kSyncClearDataTimeoutInSeconds = 60;  // 1 minute.
+
 ProfileSyncService::ProfileSyncService(ProfileSyncFactory* factory,
                                        Profile* profile,
                                        const std::string& cros_user)
@@ -445,6 +447,9 @@ void ProfileSyncService::Shutdown(bool sync_disabled) {
 
 void ProfileSyncService::ClearServerData() {
   clear_server_data_state_ = CLEAR_CLEARING;
+  clear_server_data_timer_.Start(
+      base::TimeDelta::FromSeconds(kSyncClearDataTimeoutInSeconds), this,
+      &ProfileSyncService::OnClearServerDataTimeout);
   backend_->RequestClearServerData();
 }
 
@@ -606,14 +611,36 @@ void ProfileSyncService::OnStopSyncingPermanently() {
   DisableForUser();
 }
 
+void ProfileSyncService::OnClearServerDataTimeout() {
+  if (clear_server_data_state_ != CLEAR_SUCCEEDED &&
+      clear_server_data_state_ != CLEAR_FAILED) {
+    clear_server_data_state_ = CLEAR_FAILED;
+    FOR_EACH_OBSERVER(Observer, observers_, OnStateChanged());
+  }
+}
+
 void ProfileSyncService::OnClearServerDataFailed() {
-  clear_server_data_state_ = CLEAR_FAILED;
-  FOR_EACH_OBSERVER(Observer, observers_, OnStateChanged());
+  clear_server_data_timer_.Stop();
+
+  // Only once clear has succeeded there is no longer a need to transition to
+  // a failed state as sync is disabled locally.  Also, no need to fire off
+  // the observers if the state didn't change (i.e. it was FAILED before).
+  if (clear_server_data_state_ != CLEAR_SUCCEEDED &&
+      clear_server_data_state_ != CLEAR_FAILED) {
+    clear_server_data_state_ = CLEAR_FAILED;
+    FOR_EACH_OBSERVER(Observer, observers_, OnStateChanged());
+  }
 }
 
 void ProfileSyncService::OnClearServerDataSucceeded() {
-  clear_server_data_state_ = CLEAR_SUCCEEDED;
-  FOR_EACH_OBSERVER(Observer, observers_, OnStateChanged());
+  clear_server_data_timer_.Stop();
+
+  // Even if the timout fired, we still transition to the succeeded state as
+  // we want UI to update itself and no longer allow the user to press "clear"
+  if (clear_server_data_state_ != CLEAR_SUCCEEDED) {
+    clear_server_data_state_ = CLEAR_SUCCEEDED;
+    FOR_EACH_OBSERVER(Observer, observers_, OnStateChanged());
+  }
 }
 
 void ProfileSyncService::ShowLoginDialog(gfx::NativeWindow parent_window) {