[Most Visited] Check for Sync state when using SuggestionsService.

components/suggestions/suggestions_service.cc

Index: components/suggestions/suggestions_service.cc
diff --git a/components/suggestions/suggestions_service.cc b/components/suggestions/suggestions_service.cc
index db1e3fc9632156cf08337286ea1201c93acd7051..87fc372dd382e9894cc7398195ee2692a153c440 100644
--- a/components/suggestions/suggestions_service.cc
+++ b/components/suggestions/suggestions_service.cc
@@ -156,8 +156,20 @@ bool SuggestionsService::IsControlGroup() {
 }
 
 void SuggestionsService::FetchSuggestionsData(
+    SyncState sync_state,
     SuggestionsService::ResponseCallback callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  if (sync_state == NOT_INITIALIZED_ENABLED) {
+    // Sync is not initialized yet, but enabled. Serve previously cached
+    // suggestions if available.
+    waiting_requestors_.push_back(callback);
+    ServeFromCache();
+    return;
+  } else if (sync_state == DISABLED) {
+    suggestions_store_->ClearSuggestions();

[manzagop (departed), 2014/08/20 15:43:51]

Also cancel any ongoing request and serve the waiting requestors? 

Well... not sure if it's a blacklist request. Also, if we have stuff in the
blacklist store, we'll keep kicking off new requests as we get responses. So
we'll keep filling the cache.

Basically, what's the stance on stopping syncing (all / only history). Does it
apply to the content of the blacklist store, or is the user expectation that it
should be uploaded since it was blacklisted before the change?

[Mathieu, 2014/08/20 18:41:29]

We shouldn't interact with the server anymore when sync is disabled.

+    callback.Run(SuggestionsProfile());
+    return;
+  }
 
   FetchSuggestionsDataNoTimeout(callback);