[assistant] remove deprecated pref

Remove kVoiceInteractionPrefSynced pref

BUG=None
TEST=locally build and run

Change-Id: I5caf0e6d4833abdbb2e2ba9828feea22c8697734
Reviewed-on: https://chromium-review.googlesource.com/764573Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Commit-Queue: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515775}

chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.cc

@@ -372,9 +372,6 @@ void ArcVoiceInteractionFrameworkService::OnArcPlayStoreEnabledChanged(
   if (enabled)
     return;
 
-  PrefService* prefs = Profile::FromBrowserContext(context_)->GetPrefs();
-  // TODO(xiaohuic): remove deprecated prefs::kVoiceInteractionPrefSynced.
-  prefs->SetBoolean(prefs::kVoiceInteractionPrefSynced, false);
   SetVoiceInteractionSetupCompletedInternal(false);
   SetVoiceInteractionEnabled(false, base::BindOnce(&DoNothing<bool>));
   SetVoiceInteractionContextEnabled(false);

components/arc/arc_prefs.cc

@@ -64,11 +64,6 @@ const char kVoiceInteractionEnabled[] = "settings.voice_interaction.enabled";
 // screen).
 const char kVoiceInteractionContextEnabled[] =
     "settings.voice_interaction.context.enabled";
-// A preference indicating whether voice interaction settings have been read
-// from ARC. This synchronization only happens when user goes through the flow
-// to set up voice interaction.
-const char kVoiceInteractionPrefSynced[] =
-    "settings.voice_interaction.context.synced";
 
 void RegisterProfilePrefs(PrefRegistrySimple* registry) {
   // TODO(dspaid): Implement a mechanism to allow this to sync on first boot
@@ -99,7 +94,6 @@ void RegisterProfilePrefs(PrefRegistrySimple* registry) {
   registry->RegisterBooleanPref(kSmsConnectEnabled, true);
   registry->RegisterBooleanPref(kVoiceInteractionContextEnabled, false);
   registry->RegisterBooleanPref(kVoiceInteractionEnabled, false);
-  registry->RegisterBooleanPref(kVoiceInteractionPrefSynced, false);
 }
 
 }  // namespace prefs

components/arc/arc_prefs.h

@@ -31,7 +31,6 @@ ARC_EXPORT extern const char kEcryptfsMigrationStrategy[];
 ARC_EXPORT extern const char kSmsConnectEnabled[];
 ARC_EXPORT extern const char kVoiceInteractionEnabled[];
 ARC_EXPORT extern const char kVoiceInteractionContextEnabled[];
-ARC_EXPORT extern const char kVoiceInteractionPrefSynced[];
 
 void RegisterProfilePrefs(PrefRegistrySimple* registry);