Merge "MessageStack.updateFreelist(): return whether messages were removed" into main

    /**

     * Iterates through messages and creates a reverse-ordered chain of messages to remove.

     * @return true if any messages were removed, false otherwise

     */

    public void updateFreelist(MessageQueue.MessageCompare compare, Handler h, int what,

    public boolean updateFreelist(MessageQueue.MessageCompare compare, Handler h, int what,

            Object object, Runnable r, long when) {

        Message current = (Message) sTop.getAcquire(this);

        Message prev = null;

            current = current.next;

        }

        if (firstRemoved != null) {

            Message freelist;

            do {

                freelist = mFreelistHeadValue;

                firstRemoved.nextFree = freelist;

            // prev points to the last to-be-removed message that was processed.

            } while (!sFreelistHead.compareAndSet(this, freelist, prev));

            return true;

        }

        return false;

    }

    /**

        Handler h = new Handler(Looper.getMainLooper());

        int removeWhat = 1;

        int keepWhat = 2;

        int neverPushedWhat = 3;

        // Interleave to-remove and to-keep messages.

        for (int i = 0; i < 5; i++) {

            stack.pushMessage(Message.obtain(h, keepWhat));

        }

        stack.heapSweep();

        stack.updateFreelist(new MessageQueue.MatchHandlerWhatAndObject(),

                h, removeWhat, null, null, 0);

        assertTrue(stack.updateFreelist(new MessageQueue.MatchHandlerWhatAndObject(),

                h, removeWhat, null, null, 0));

        // Try deleting a message we never pushed

        assertFalse(stack.updateFreelist(new MessageQueue.MatchHandlerWhatAndObject(),

                h, neverPushedWhat, null, null, 0));

        assertEquals(5, stack.freelistSizeForTest());

        stack.drainFreelist();