Fixing memory leaks in the accessiiblity layer.

1. AccessibilityInteractionConnections were removed from the
   AccessiiblityManagerService but their DeathRecipents were
   not unregistered, thus every removed interaction connection
   was essentially leaking. Such connection is registered in
   the system for every ViewRootImpl when accessiiblity is
   enabled and inregistered when disabled.

2. Every AccessibilityEvent and AccessiilbityEventInfo obtained
   from a widnow content querying accessibility service had a
   handle to a binder proxy over which to make queries. Hoewever,
   holding a proxy to a remote binder prevents the latter from
   being garbage collected. Therefore, now the events and infos
   have a connection id insteand and the hindden singleton
   AccessiiblityInteaction client via which queries are made
   has a registry with the connections. This class looks up
   the connection given its id before making an IPC. Now the
   connection is stored in one place and when an accessibility
   service is disconnected the system sets the connection to
   null so the binder object in the system process can be GCed.
   Note that before this change a bad implemented accessibility
   service could cache events or infos causing a leak in the
   system process. This should never happen.

3. SparseArray was not clearing the reference to the last moved
   element while garbage collecting thus causing a leak.

bug:5664337

Change-Id: Id397f614b026d43bd7b57bb7f8186bca5cdfcff9

1 files changed, 1 insertions, 0 deletions

diff --git a/core/java/android/util/SparseArray.java b/core/java/android/util/SparseArray.java
index 7cf4579..366abd3 100644
--- a/core/java/android/util/SparseArray.java
+++ b/core/java/android/util/SparseArray.java
@@ -134,6 +134,7 @@ public class SparseArray<E> implements Cloneable {
                 if (i != o) {
                     keys[o] = keys[i];
                     values[o] = val;
+                    values[i] = null;
                 }
 
                 o++;