Work around for HDMI audio output rediscovering transistion loss.

chromeos/audio/cras_audio_handler_unittest.cc

Index: chromeos/audio/cras_audio_handler_unittest.cc
diff --git a/chromeos/audio/cras_audio_handler_unittest.cc b/chromeos/audio/cras_audio_handler_unittest.cc
index fa5dbc35ba60a5c266c49f4c1517455b8022c1ae..7472a7f16341c747967c360ef48862b287866090 100644
--- a/chromeos/audio/cras_audio_handler_unittest.cc
+++ b/chromeos/audio/cras_audio_handler_unittest.cc
@@ -4,9 +4,12 @@
 
 #include "chromeos/audio/cras_audio_handler.h"
 
+#include "base/bind.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "base/thread_task_runner_handle.h"
 #include "base/values.h"
 #include "chromeos/audio/audio_devices_pref_handler_stub.h"
 #include "chromeos/dbus/audio_node.h"
@@ -343,6 +346,18 @@ class CrasAudioHandlerTest : public testing::Test {
     return num_active_nodes;
   }
 
+  void SetActiveHDMIRediscover() {
+    cras_audio_handler_->SetActiveHDMIOutoutRediscoveringIfNecessary(true);
+  }
+
+  void SetHDMIRediscoverGracePeriodDuration(int duration_in_ms) {
+    cras_audio_handler_->SetHDMIRediscoverGracePeriodForTesting(duration_in_ms);
+  }
+
+  bool IsDuringHDMIRediscoverGracePeriod() {
+    return cras_audio_handler_->hdmi_rediscovering();
+  }
+
  protected:
   base::MessageLoopForUI message_loop_;
   CrasAudioHandler* cras_audio_handler_;  // Not owned.
@@ -354,6 +369,46 @@ class CrasAudioHandlerTest : public testing::Test {
   DISALLOW_COPY_AND_ASSIGN(CrasAudioHandlerTest);
 };
 
+class HDMIRediscoverWaiter {
+ public:
+  HDMIRediscoverWaiter(CrasAudioHandlerTest* cras_audio_handler_test,
+                       int grace_period_duration_in_ms)
+      : cras_audio_handler_test_(cras_audio_handler_test),
+        grace_period_duration_in_ms_(grace_period_duration_in_ms) {}
+
+  void WaitUntilTimeOut(int wait_duration_in_ms) {
+    base::RunLoop run_loop;
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+        FROM_HERE, run_loop.QuitClosure(),
+        base::TimeDelta::FromMilliseconds(wait_duration_in_ms));
+    run_loop.Run();
+  }
+
+  void CheckHDMIRediscoverGracePeriodEnd(const base::Closure& quit_loop_func) {
+    if (!cras_audio_handler_test_->IsDuringHDMIRediscoverGracePeriod()) {
+      quit_loop_func.Run();
+      return;
+    }
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&HDMIRediscoverWaiter::CheckHDMIRediscoverGracePeriodEnd,
+                   base::Unretained(this), quit_loop_func),
+        base::TimeDelta::FromMilliseconds(grace_period_duration_in_ms_ / 4));
+  }
+
+  void WaitUntilHDMIRediscoverGracePeriodEnd() {
+    base::RunLoop run_loop;
+    CheckHDMIRediscoverGracePeriodEnd(run_loop.QuitClosure());
+    run_loop.Run();
+  }
+
+ private:
+  CrasAudioHandlerTest* cras_audio_handler_test_;  // not owned
+  int grace_period_duration_in_ms_;
+
+  DISALLOW_COPY_AND_ASSIGN(HDMIRediscoverWaiter);
+};
+
 TEST_F(CrasAudioHandlerTest, InitializeWithOnlyDefaultAudioDevices) {
   AudioNodeList audio_nodes;
   audio_nodes.push_back(kInternalSpeaker);
@@ -2493,4 +2548,53 @@ TEST_F(CrasAudioHandlerTest, ActiveNodeLostDuringLoginSession) {
   EXPECT_TRUE(headphone_resumed->active);
 }
 
+// This test HDMI output rediscovering case in crbug.com/503667.
+TEST_F(CrasAudioHandlerTest, HDMIOutputRediscover) {
+  AudioNodeList audio_nodes;
+  audio_nodes.push_back(kInternalSpeaker);
+  audio_nodes.push_back(kHDMIOutput);
+  SetUpCrasAudioHandler(audio_nodes);
+
+  // Verify the HDMI device has been selected as the active output, and audio
+  // output is not muted.
+  AudioDevice active_output;
+  EXPECT_TRUE(
+      cras_audio_handler_->GetPrimaryActiveOutputDevice(&active_output));
+  EXPECT_EQ(kHDMIOutput.id, active_output.id);
+  EXPECT_EQ(kHDMIOutput.id, cras_audio_handler_->GetPrimaryActiveOutputNode());
+  EXPECT_TRUE(cras_audio_handler_->has_alternative_output());
+  EXPECT_FALSE(cras_audio_handler_->IsOutputMuted());
+
+  // Trigger HDMI rediscovering grace period, and remove the HDMI node.
+  const int grace_period_in_ms = 200;
+  SetHDMIRediscoverGracePeriodDuration(grace_period_in_ms);
+  SetActiveHDMIRediscover();
+  AudioNodeList audio_nodes_lost_hdmi;
+  audio_nodes_lost_hdmi.push_back(kInternalSpeaker);
+  ChangeAudioNodes(audio_nodes_lost_hdmi);
+
+  // Verify the active output is switched to internal speaker, it is not muted
+  // by preference, but the system output is muted during the grace period.
+  EXPECT_TRUE(
+      cras_audio_handler_->GetPrimaryActiveOutputDevice(&active_output));
+  EXPECT_EQ(kInternalSpeaker.id, active_output.id);
+  EXPECT_FALSE(
+      cras_audio_handler_->IsOutputMutedForDevice(kInternalSpeaker.id));
+  EXPECT_TRUE(cras_audio_handler_->IsOutputMuted());
+
+  // Re-attach the HDMI device after a little delay.
+  HDMIRediscoverWaiter waiter(this, grace_period_in_ms);
+  waiter.WaitUntilTimeOut(grace_period_in_ms / 4);
+  ChangeAudioNodes(audio_nodes);
+
+  // After HDMI re-discover grace period, verify HDMI output is selected as the
+  // active device and not muted.
+  waiter.WaitUntilHDMIRediscoverGracePeriodEnd();
+  EXPECT_TRUE(
+      cras_audio_handler_->GetPrimaryActiveOutputDevice(&active_output));
+  EXPECT_EQ(kHDMIOutput.id, active_output.id);
+  EXPECT_EQ(kHDMIOutput.id, cras_audio_handler_->GetPrimaryActiveOutputNode());
+  EXPECT_FALSE(cras_audio_handler_->IsOutputMuted());
+}
+
 }  // namespace chromeos