EVDA: Preserve resolution change event across reset.

The codec maintains current resolution as a part of its state and carries it
over across the streamoff/streamon (i.e. Reset) sequence. The resolution change
event should thus not be discarded if it arrives before Reset and is not
addressed there, as it will be valid after Reset as well and should be
addressed then.

EVDA::DecodeBufferInitial() does not handle potential resolution changes (i.e.
it discards GetFormat() results) after Reset(), which is fine, because we
rely on the event to be informed about the resolution change instead.

Also the DCHECK, which verifies that we don't dequeue events in other states
than kDecoding, is not correct, because we might have to dequeue one in kAfterReset.

BUG=316074
TEST=vdatest, video playback, MSE, seek torture tests

Review URL: https://codereview.chromium.org/70183003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235559 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 7 insertions, 4 deletions

diff --git a/content/common/gpu/media/exynos_video_decode_accelerator.cc b/content/common/gpu/media/exynos_video_decode_accelerator.cc
index 9f0f57a..26fe624 100644
--- a/content/common/gpu/media/exynos_video_decode_accelerator.cc
+++ b/content/common/gpu/media/exynos_video_decode_accelerator.cc
@@ -1075,7 +1075,7 @@ void ExynosVideoDecodeAccelerator::EnqueueMfc() {
 
 void ExynosVideoDecodeAccelerator::DequeueMfcEvents() {
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
-  DCHECK_EQ(decoder_state_, kDecoding);
+  DCHECK_NE(decoder_state_, kUninitialized);
   DVLOG(3) << "DequeueMfcEvents()";
 
   struct v4l2_event ev;
@@ -1389,9 +1389,6 @@ void ExynosVideoDecodeAccelerator::ResetTask() {
   if (!StopDevicePoll(false))
     return;
 
-  DequeueMfcEvents();
-
-  resolution_change_pending_ = false;
   decoder_current_bitstream_buffer_.reset();
   while (!decoder_input_queue_.empty())
     decoder_input_queue_.pop();
@@ -1420,6 +1417,12 @@ void ExynosVideoDecodeAccelerator::ResetDoneTask() {
     return;
   }
 
+  // We might have received a resolution change event while we were waiting
+  // for the reset to finish. The codec will not post another event if the
+  // resolution after reset remains the same as the one to which were just
+  // about to switch, so preserve the event across reset so we can address
+  // it after resuming.
+
   // Reset format-specific bits.
   if (video_profile_ >= media::H264PROFILE_MIN &&
       video_profile_ <= media::H264PROFILE_MAX) {