media/gpu/test: Add multiple outstanding encodes test to video encoder tests.

This CL adds a new test to the video_encode_accelerator_tests that
tests multiple outstanding simultaneous encodes.

Bug: 1045825
Test: ./video_encode_accelerator_tests on hana
Change-Id: Iaf7be2b3292b3efd1f7d830dd2d01bd59790ce7c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2251610
Commit-Queue: David Staessens <dstaessens@chromium.org>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792577}

media/gpu/test/video_encoder/video_encoder_client.cc

@@ -396,7 +396,8 @@ void VideoEncoderClient::FlushTask() {
   // If the encoder does not support flush, immediately consider flushing done.
   if (!encoder_->IsFlushSupported()) {
     FireEvent(VideoEncoder::EncoderEvent::kFlushing);
-    FlushDoneTask(true);
+    if (num_outstanding_encode_requests_ == 0)
+      FlushDoneTask(true);
     return;
   }
 
@@ -424,9 +425,17 @@ void VideoEncoderClient::EncodeDoneTask(base::TimeDelta timestamp) {
   DCHECK_NE(VideoEncoderClientState::kIdle, encoder_client_state_);
   DVLOGF(4);
 
+  FireEvent(VideoEncoder::EncoderEvent::kFrameReleased);
+
   num_outstanding_encode_requests_--;
 
-  FireEvent(VideoEncoder::EncoderEvent::kFrameReleased);
+  // If the encoder does not support flushing, we have to manually call
+  // FlushDoneTask() when the last outstanding encode has been completed.
+  if ((encoder_client_state_ == VideoEncoderClientState::kFlushing) &&
+      !encoder_->IsFlushSupported() &&
+      (num_outstanding_encode_requests_ == 0)) {
+    FlushDoneTask(true);
+  }
 
   // Queue the next frame to be encoded.
   encoder_client_task_runner_->PostTask(

media/gpu/video_encode_accelerator_tests.cc

@@ -257,6 +257,21 @@ TEST_F(VideoEncoderTest, DestroyBeforeInitialize) {
   EXPECT_NE(video_encoder, nullptr);
 }
 
+// Encode video from start to end. Multiple buffer encodes will be queued in the
+// encoder, without waiting for the result of the previous encode requests.
+TEST_F(VideoEncoderTest, FlushAtEndOfStream_MultipleOutstandingDecodes) {
+  VideoEncoderClientConfig config(g_env->Video(), g_env->Profile());
+  config.max_outstanding_encode_requests = 4;
+  auto encoder = CreateVideoEncoder(g_env->Video(), config);
+
+  encoder->Encode();
+  EXPECT_TRUE(encoder->WaitForFlushDone());
+
+  EXPECT_EQ(encoder->GetFlushDoneCount(), 1u);
+  EXPECT_EQ(encoder->GetFrameReleasedCount(), g_env->Video()->NumFrames());
+  EXPECT_TRUE(encoder->WaitForBitstreamProcessors());
+}
+
 // Encode multiple videos simultaneously from start to finish.
 TEST_F(VideoEncoderTest, FlushAtEndOfStream_MultipleConcurrentEncodes) {
   // The minimal number of concurrent encoders we expect to be supported.