[Sync] Support open tabs experiment enabling before sync setup completion.

chrome/browser/sync/glue/sync_backend_host.cc

Index: chrome/browser/sync/glue/sync_backend_host.cc
diff --git a/chrome/browser/sync/glue/sync_backend_host.cc b/chrome/browser/sync/glue/sync_backend_host.cc
index 1c4368308e5d4856eeba271ceeed24d18a9b4758..d36e1ee8e4e425c916ea0a305f00f104e774e063 100644
--- a/chrome/browser/sync/glue/sync_backend_host.cc
+++ b/chrome/browser/sync/glue/sync_backend_host.cc
@@ -820,8 +820,7 @@ void SyncBackendHost::Core::HandleSyncCycleCompletedOnFrontendLoop(
   // Process any changes to the datatypes we're syncing.
   // TODO(sync): add support for removing types.
   syncable::ModelTypeSet to_add;
-  if (host_->initialized() &&
-      sync_manager()->ReceivedExperimentalTypes(&to_add)) {
+  if (sync_manager()->ReceivedExperimentalTypes(&to_add)) {

[akalin, 2011/10/14 23:18:48]

hmm.  Thinking about this, I think it's cleaner to just cache to_add if not
initialized yet and call OnDataTypesChanged after we do initialize (in
HandleInitializationCompleteOnFrontendLoop).  I'm wary of making some functions
callable when uninitialized and some not.  Although it's a pain because it would
add an extra member variable and have two places to do the same thing.

Maybe have a helper fn:

SBH::AddExperimentalTypes() {
  CHECK(initialized());
  ModelTypeSet to_add;
  if (sync_manager()->Received..()) {
    frontend_->OnDataTypesChanged(...);
  }
}

and then here:

if (host->initialized()) {
  host->AddExperimentalTypes();
}

and in HandleInitializationCompleteOnFrontendLoop:

case REFRESHING_ENCRYPTION:
  initialization_state_ = INITIALIZED;
  frontend_->OnBackendInitialized(...);
  AddExperimentalTypes();

[Nicolas Zea, 2011/10/15 00:31:35]

Done.

     host_->frontend_->OnDataTypesChanged(to_add);
   }