Crash in ViewRootImpl when accessibility is on.

We fire view subtree mutation events every X amount of time.
It was possible that the runnable that fires an event to be
scheduled more than once while this should not happen. As
a result there was a crash since we did not expect to have
a second run and nullified a reference.

bug:9422804

Change-Id: I914e163b026cd217e1536ab0ed3a6b11113c2c73

1 files changed, 1 insertions, 1 deletions

diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 109b8e00ea46..9ec90ef4d186 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -6449,8 +6449,8 @@ public final class ViewRootImpl implements ViewParent,
             final long timeSinceLastMillis = SystemClock.uptimeMillis() - mLastEventTimeMillis;
             final long minEventIntevalMillis =
                     ViewConfiguration.getSendRecurringAccessibilityEventsInterval();
+            mSource.removeCallbacks(this);
             if (timeSinceLastMillis >= minEventIntevalMillis) {
-                mSource.removeCallbacks(this);
                 run();
             } else {
                 mSource.postDelayed(this, minEventIntevalMillis - timeSinceLastMillis);