[Cast] Fix chromium build errors in display settings

This is a fixup for b2af6d84.

- add/remove macros.
- avoid inline virtual function.

Bug: b/162546246
Bug: b/173504008
Test: None
Change-Id: I3aa2767efc30bf0e677462f395be50dbefc4117f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2581438Reviewed-by: Sean Topping <seantopping@chromium.org>
Commit-Queue: Mingyu Kang <kenkangxgwe@google.com>
Cr-Commit-Position: refs/heads/master@{#835316}

chromecast/ui/display_settings/screen_power_controller_default.cc

@@ -52,6 +52,8 @@ void ScreenPowerControllerDefault::SetAllowScreenPowerOff(
       << "Screen is not allowed to be powered off. Please enable AURA.";
 }
 
-}  // namespace chromecast
+bool ScreenPowerControllerDefault::IsScreenOn() const {
+  return screen_on_;
+}
 
-#endif  // CHROMECAST_UI_DISPLAY_SETTINGS_BRIGHTNESS_ANIMATION_H_
+}  // namespace chromecast

chromecast/ui/display_settings/screen_power_controller_default.h

@@ -22,7 +22,7 @@ class ScreenPowerControllerDefault : public ScreenPowerController {
   void SetScreenOn() override;
   void SetScreenOff() override;
   void SetAllowScreenPowerOff(bool allow_power_off) override;
-  inline bool IsScreenOn() const override { return screen_on_; }
+  bool IsScreenOn() const override;
 
  private:
   bool screen_on_;

chromecast/ui/display_settings_manager_impl.cc

@@ -29,6 +29,7 @@ const float kMinApiBrightness = 0.0f;
 const float kMaxApiBrightness = 1.0f;
 const float kDefaultApiBrightness = kMaxApiBrightness;
 
+#if defined(USE_AURA)
 bool CheckDisplayStatus(const base::flat_map<int64_t, bool>& statuses) {
   for (const auto& status : statuses) {
     if (!status.second) {
@@ -37,6 +38,7 @@ bool CheckDisplayStatus(const base::flat_map<int64_t, bool>& statuses) {
   }
   return true;
 }
+#endif  // defined(USE_AURA)
 
 }  // namespace
 
@@ -106,13 +108,17 @@ void DisplaySettingsManagerImpl::AddReceiver(
 }
 
 void DisplaySettingsManagerImpl::SetScreenPowerOn(PowerToggleCallback callback) {
+#if defined(USE_AURA)
   display_configurator_->EnableDisplay(
       base::BindOnce(&CheckDisplayStatus).Then(std::move(callback)));
+#endif  // defined(USE_AURA)
 }
 
 void DisplaySettingsManagerImpl::SetScreenPowerOff(PowerToggleCallback callback) {
+#if defined(USE_AURA)
   display_configurator_->DisableDisplay(
       base::BindOnce(&CheckDisplayStatus).Then(std::move(callback)));
+#endif  // defined(USE_AURA)
 }
 
 void DisplaySettingsManagerImpl::SetScreenBrightnessOn(