Add MetalayerMode to the palette.

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

Index: chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.h
diff --git a/chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.h b/chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.h
index 015acf8442b3b54f6381649f8f688b249f540750..71583e3adbd3f036ded997f7bccfa997ab3b54f2 100644
--- a/chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.h
+++ b/chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.h
@@ -42,12 +42,23 @@ class ArcVoiceInteractionFrameworkService
   void CaptureFocusedWindow(
       const CaptureFocusedWindowCallback& callback) override;
   void CaptureFullscreen(const CaptureFullscreenCallback& callback) override;
+  void OnMetalayerClosed() override;
+
+  bool IsMetalayerSupported();
+  void ShowMetalayer(const base::Closure& closed);
+  void HideMetalayer();
 
   // Whether enable-voice-interaction switch is present.
   static bool IsVoiceInteractionEnabled();
 
+  // For supporting ArcServiceManager::GetService<T>().
+  static const char kArcServiceName[];
+
  private:
+  void SetMetalayerVisibility(bool visible);
+
   mojo::Binding<mojom::VoiceInteractionFrameworkHost> binding_;
+  base::Closure metalayer_closed_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcVoiceInteractionFrameworkService);
 };