Remove some usages of FSTWriteGroup (#983)

* FSTMutationQueue no longer needs groups

* Remove write group from mutation queue entirely

* Remove write group from query cache

* Mark groups unused in remote document cache

* Drop write group entirely from remote document cache

* style

* Drop commented-out code

* Drop commented-out code

1 files changed, 2 insertions, 2 deletions

diff --git a/Firestore/Source/Local/FSTMemoryRemoteDocumentCache.mm b/Firestore/Source/Local/FSTMemoryRemoteDocumentCache.mm
index c35c23d..9289e60 100644
--- a/Firestore/Source/Local/FSTMemoryRemoteDocumentCache.mm
+++ b/Firestore/Source/Local/FSTMemoryRemoteDocumentCache.mm
@@ -45,11 +45,11 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)shutdown {
 }
 
-- (void)addEntry:(FSTMaybeDocument *)document group:(FSTWriteGroup *)group {
+- (void)addEntry:(FSTMaybeDocument *)document {
   self.docs = [self.docs dictionaryBySettingObject:document forKey:document.key];
 }
 
-- (void)removeEntryForKey:(const DocumentKey &)key group:(FSTWriteGroup *)group {
+- (void)removeEntryForKey:(const DocumentKey &)key {
   self.docs = [self.docs dictionaryByRemovingObjectForKey:key];
 }