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, 5 insertions, 9 deletions

diff --git a/Firestore/Source/Local/FSTMutationQueue.h b/Firestore/Source/Local/FSTMutationQueue.h
index c2e2548..7a43957 100644
--- a/Firestore/Source/Local/FSTMutationQueue.h
+++ b/Firestore/Source/Local/FSTMutationQueue.h
@@ -25,7 +25,6 @@
 @class FSTMutationBatch;
 @class FSTQuery;
 @class FIRTimestamp;
-@class FSTWriteGroup;
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -42,7 +41,7 @@ NS_ASSUME_NONNULL_BEGIN
  * than nextBatchID. This prevents the local store from creating new batches that the mutation
  * queue would consider erroneously acknowledged.
  */
-- (void)startWithGroup:(FSTWriteGroup *)group;
+- (void)start;
 
 /** Shuts this mutation queue down, closing open files, etc. */
 - (void)shutdown;
@@ -65,20 +64,17 @@ NS_ASSUME_NONNULL_BEGIN
 - (FSTBatchID)highestAcknowledgedBatchID;
 
 /** Acknowledges the given batch. */
-- (void)acknowledgeBatch:(FSTMutationBatch *)batch
-             streamToken:(nullable NSData *)streamToken
-                   group:(FSTWriteGroup *)group;
+- (void)acknowledgeBatch:(FSTMutationBatch *)batch streamToken:(nullable NSData *)streamToken;
 
 /** Returns the current stream token for this mutation queue. */
 - (nullable NSData *)lastStreamToken;
 
 /** Sets the stream token for this mutation queue. */
-- (void)setLastStreamToken:(nullable NSData *)streamToken group:(FSTWriteGroup *)group;
+- (void)setLastStreamToken:(nullable NSData *)streamToken;
 
 /** Creates a new mutation batch and adds it to this mutation queue. */
 - (FSTMutationBatch *)addMutationBatchWithWriteTime:(FIRTimestamp *)localWriteTime
-                                          mutations:(NSArray<FSTMutation *> *)mutations
-                                              group:(FSTWriteGroup *)group;
+                                          mutations:(NSArray<FSTMutation *> *)mutations;
 
 /** Loads the mutation batch with the given batchID. */
 - (nullable FSTMutationBatch *)lookupMutationBatch:(FSTBatchID)batchID;
@@ -150,7 +146,7 @@ NS_ASSUME_NONNULL_BEGIN
  * In both cases, the array of mutations to remove must be a contiguous range of batchIds. This is
  * most easily accomplished by loading mutations with @a -allMutationBatchesThroughBatchID:.
  */
-- (void)removeMutationBatches:(NSArray<FSTMutationBatch *> *)batches group:(FSTWriteGroup *)group;
+- (void)removeMutationBatches:(NSArray<FSTMutationBatch *> *)batches;
 
 /** Performs a consistency check, examining the mutation queue for any leaks, if possible. */
 - (void)performConsistencyCheck;