Merge "Fix a flaky test in buffer_hub-test"

  EXPECT_EQ(0, c1->AcquireAsync(&metadata, &invalid_fence));

  EXPECT_EQ(0, c1->ReleaseAsync(&metadata, invalid_fence));

  // Note that the next PDX call is on the producer channel, which may be

  // executed before Release impulse gets executed by bufferhubd. Thus, here we

  // need to wait until the releasd is confirmed before creating another

  // consumer.

  EXPECT_LT(0, RETRY_EINTR(p->Poll(kPollTimeoutMs)));

  EXPECT_TRUE(IsBufferReleased(p->buffer_state()));

  // Create another consumer immediately after the release, should not make the

  // buffer un-released. This is guaranteed by IPC execution order in bufferhubd.

  // buffer un-released.

  std::unique_ptr<BufferConsumer> c2 =

      BufferConsumer::Import(p->CreateConsumer());

  ASSERT_TRUE(c2.get() != nullptr);

  EXPECT_LT(0, RETRY_EINTR(p->Poll(kPollTimeoutMs)));

  EXPECT_TRUE(IsBufferReleased(p->buffer_state()));

  EXPECT_EQ(0, p->GainAsync(&metadata, &invalid_fence));

  EXPECT_TRUE(IsBufferGained(p->buffer_state()));