Only trigger audio notifications on change

BUG=225531

Review URL: https://codereview.chromium.org/13144023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@191878 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 29 insertions, 10 deletions

diff --git a/chrome/browser/chromeos/audio/audio_handler.cc b/chrome/browser/chromeos/audio/audio_handler.cc
index b0f83d8..7e81a12 100644
--- a/chrome/browser/chromeos/audio/audio_handler.cc
+++ b/chrome/browser/chromeos/audio/audio_handler.cc
@@ -109,7 +109,10 @@ void AudioHandler::SetVolumePercent(double volume_percent) {
 void AudioHandler::SetVolumePercentInternal(double volume_percent) {
   mixer_->SetVolumePercent(volume_percent);
   local_state_->SetDouble(prefs::kAudioVolumePercent, volume_percent);
-  FOR_EACH_OBSERVER(VolumeObserver, volume_observers_, OnVolumeChanged());
+  if (volume_percent != volume_percent_) {
+    volume_percent_ = volume_percent;
+    FOR_EACH_OBSERVER(VolumeObserver, volume_observers_, OnVolumeChanged());
+  }
 }
 
 void AudioHandler::AdjustVolumeByPercent(double adjust_by_percent) {
@@ -133,7 +136,10 @@ void AudioHandler::SetMuted(bool mute) {
         SetVolumePercentInternal(kDefaultUnmuteVolumePercent);
       }
     }
-    FOR_EACH_OBSERVER(VolumeObserver, volume_observers_, OnMuteToggled());
+    if (mute != muted_) {
+      muted_ = mute;
+      FOR_EACH_OBSERVER(VolumeObserver, volume_observers_, OnMuteToggled());
+    }
   }
 }
 
@@ -156,12 +162,17 @@ void AudioHandler::RemoveVolumeObserver(VolumeObserver* observer) {
 
 AudioHandler::AudioHandler(AudioMixer* mixer)
     : mixer_(mixer),
-      local_state_(g_browser_process->local_state()) {
+      local_state_(g_browser_process->local_state()),
+      volume_percent_(0),
+      muted_(false) {
   InitializePrefObservers();
   mixer_->Init();
   ApplyAudioPolicy();
-  SetMuted(local_state_->GetInteger(prefs::kAudioMute) == kPrefMuteOn);
-  SetVolumePercentInternal(local_state_->GetDouble(prefs::kAudioVolumePercent));
+  // Set initial state so that notifications are not triggered.
+  muted_ = (local_state_->GetInteger(prefs::kAudioMute) == kPrefMuteOn);
+  volume_percent_ = local_state_->GetDouble(prefs::kAudioVolumePercent);
+  SetMuted(muted_);
+  SetVolumePercentInternal(volume_percent_);
 }
 
 AudioHandler::~AudioHandler() {
@@ -178,14 +189,19 @@ void AudioHandler::InitializePrefObservers() {
 
 void AudioHandler::ApplyAudioPolicy() {
   mixer_->SetMuteLocked(false);
+  bool muted = false;
   if (local_state_->GetBoolean(prefs::kAudioOutputAllowed)) {
-    mixer_->SetMuted(
-        local_state_->GetInteger(prefs::kAudioMute) == kPrefMuteOn);
+    muted = (local_state_->GetInteger(prefs::kAudioMute) == kPrefMuteOn);
+    mixer_->SetMuted(muted);
   } else {
-    mixer_->SetMuted(true);
+    muted = true;
+    mixer_->SetMuted(muted);
     mixer_->SetMuteLocked(true);
   }
-  FOR_EACH_OBSERVER(VolumeObserver, volume_observers_, OnMuteToggled());
+  if (muted_ != muted) {
+    muted_ = muted;
+    FOR_EACH_OBSERVER(VolumeObserver, volume_observers_, OnMuteToggled());
+  }
   mixer_->SetCaptureMuteLocked(false);
   if (local_state_->GetBoolean(prefs::kAudioCaptureAllowed)) {
     mixer_->SetCaptureMuted(false);
diff --git a/chrome/browser/chromeos/audio/audio_handler.h b/chrome/browser/chromeos/audio/audio_handler.h
index 36bbb81..b8e318c 100644
--- a/chrome/browser/chromeos/audio/audio_handler.h
+++ b/chrome/browser/chromeos/audio/audio_handler.h
@@ -100,6 +100,10 @@ class AudioHandler {
 
   PrefChangeRegistrar pref_change_registrar_;
 
+  // Track state for triggering callbacks
+  double volume_percent_;
+  bool muted_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioHandler);
 };
 
diff --git a/chrome/browser/policy/policy_browsertest.cc b/chrome/browser/policy/policy_browsertest.cc
index 547fd57..8cf7546 100644
--- a/chrome/browser/policy/policy_browsertest.cc
+++ b/chrome/browser/policy/policy_browsertest.cc
@@ -1658,7 +1658,6 @@ IN_PROC_BROWSER_TEST_F(PolicyTest, DisableAudioOutput) {
   bool prior_state = audio_handler->IsMuted();
   // Make sure we are not muted and then toggle the policy and observe if the
   // trigger was successful.
-  EXPECT_CALL(*mock, OnMuteToggled()).Times(1);
   audio_handler->SetMuted(false);
   EXPECT_FALSE(audio_handler->IsMuted());
   EXPECT_CALL(*mock, OnMuteToggled()).Times(1);