Revert "[NS A24] Add an object to represent changes in assignment"

This reverts commit c375dccad3b164251b49f44267423cf0640209d7.

Reason for revert: Toggling wifi on/off causes networking to
 stop working with these four patches applied.
Bug: 146230156

Change-Id: Ie0217796c89abf0dc86e6a4f8324811155dc57cd
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index c6f06f1..f8f685d 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -6296,26 +6296,6 @@
         }
     }
 
-    // An accumulator class to gather the list of changes that result from a rematch.
-    // TODO : enrich to represent an entire set of changes to apply.
-    private static class NetworkReassignment {
-        static class NetworkBgStatePair {
-            @NonNull final NetworkAgentInfo mNetwork;
-            final boolean mOldBackground;
-            NetworkBgStatePair(@NonNull final NetworkAgentInfo network,
-                    final boolean oldBackground) {
-                mNetwork = network;
-                mOldBackground = oldBackground;
-            }
-        }
-
-        @NonNull private final Set<NetworkBgStatePair> mRematchedNetworks = new ArraySet<>();
-
-        void addRematchedNetwork(@NonNull final NetworkBgStatePair network) {
-            mRematchedNetworks.add(network);
-        }
-    }
-
     private ArrayMap<NetworkRequestInfo, NetworkAgentInfo> computeRequestReassignmentForNetwork(
             @NonNull final NetworkAgentInfo newNetwork) {
         final int score = newNetwork.getCurrentScore();
@@ -6361,8 +6341,8 @@
     //   needed. A network is needed if it is the best network for
     //   one or more NetworkRequests, or if it is a VPN.
     //
-    // - Writes into the passed reassignment object all changes that should be done for
-    //   rematching this network with all requests, to be applied later.
+    // - Tears down newNetwork if it just became validated
+    //   but turns out to be unneeded.
     //
     // NOTE: This function only adds NetworkRequests that "newNetwork" could satisfy,
     // it does not remove NetworkRequests that other Networks could better satisfy.
@@ -6370,23 +6350,15 @@
     // This function should be used when possible instead of {@code rematchAllNetworksAndRequests}
     // as it performs better by a factor of the number of Networks.
     //
-    // TODO : stop writing to the passed reassignment. This is temporarily more useful, but
-    // it's unidiomatic Java and it's hard to read.
-    //
-    // @param changes a currently-building list of changes to write to
     // @param newNetwork is the network to be matched against NetworkRequests.
     // @param now the time the rematch starts, as returned by SystemClock.elapsedRealtime();
-    private void rematchNetworkAndRequests(@NonNull final NetworkReassignment changes,
-            @NonNull final NetworkAgentInfo newNetwork, final long now) {
+    private void rematchNetworkAndRequests(NetworkAgentInfo newNetwork, long now) {
         ensureRunningOnConnectivityServiceThread();
         if (!newNetwork.everConnected) return;
         boolean isNewDefault = false;
         NetworkAgentInfo oldDefaultNetwork = null;
 
         final boolean wasBackgroundNetwork = newNetwork.isBackgroundNetwork();
-        changes.addRematchedNetwork(new NetworkReassignment.NetworkBgStatePair(newNetwork,
-                wasBackgroundNetwork));
-
         final int score = newNetwork.getCurrentScore();
 
         if (VDBG || DDBG) log("rematching " + newNetwork.name());
@@ -6543,9 +6515,8 @@
         // scoring network and then a higher scoring network, which could produce multiple
         // callbacks.
         Arrays.sort(nais);
-        final NetworkReassignment changes = new NetworkReassignment();
         for (final NetworkAgentInfo nai : nais) {
-            rematchNetworkAndRequests(changes, nai, now);
+            rematchNetworkAndRequests(nai, now);
         }
 
         final NetworkAgentInfo newDefaultNetwork = getDefaultNetwork();