Introduce ReferenceDelegates (#1222)

* Bump sequence number on resume token refresh

* Style

* Fix comment formatting

* Add FSTReferenceDelegate definition and documentation

* Add methods to return nil for delegates, wire up inMemoryPins

* Add hook for removing a reference

* Start work on reference delegates

* Fix up tests to support adding documents at a sequence number

* Implement removing references

* Remove from target when dropped from local view

* Fix warning

* Add hooks for removal from mutation queue

* Add hooks for limbo document updates

* Style

* Drop commented-out code

* Fixup after merging master

* Drop sequence number plumbing

* Style

* Drop errant semicolon

1 files changed, 6 insertions, 2 deletions

diff --git a/Firestore/Source/Local/FSTMemoryPersistence.mm b/Firestore/Source/Local/FSTMemoryPersistence.mm
index 8d74881..3466f3e 100644
--- a/Firestore/Source/Local/FSTMemoryPersistence.mm
+++ b/Firestore/Source/Local/FSTMemoryPersistence.mm
@@ -59,7 +59,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)init {
   if (self = [super init]) {
-    _queryCache = [[FSTMemoryQueryCache alloc] init];
+    _queryCache = [[FSTMemoryQueryCache alloc] initWithPersistence:self];
     _remoteDocumentCache = [[FSTMemoryRemoteDocumentCache alloc] init];
   }
   return self;
@@ -78,6 +78,10 @@ NS_ASSUME_NONNULL_BEGIN
   self.started = NO;
 }
 
+- (_Nullable id<FSTReferenceDelegate>)referenceDelegate {
+  return nil;
+}
+
 - (const FSTTransactionRunner &)run {
   return _transactionRunner;
 }
@@ -85,7 +89,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (id<FSTMutationQueue>)mutationQueueForUser:(const User &)user {
   id<FSTMutationQueue> queue = _mutationQueues[user];
   if (!queue) {
-    queue = [FSTMemoryMutationQueue mutationQueue];
+    queue = [[FSTMemoryMutationQueue alloc] initWithPersistence:self];
     _mutationQueues[user] = queue;
   }
   return queue;