arc-bridge: Introduce the ArcService class

components/arc/clipboard/arc_clipboard_bridge.h

Index: components/arc/clipboard/arc_clipboard_bridge.h
diff --git a/components/arc/clipboard/arc_clipboard_bridge.h b/components/arc/clipboard/arc_clipboard_bridge.h
index d458f63f07d92ba4f68266dcd220857fb6128b64..13929933872e1268906e26c20cd904e5c3e290b5 100644
--- a/components/arc/clipboard/arc_clipboard_bridge.h
+++ b/components/arc/clipboard/arc_clipboard_bridge.h
@@ -9,11 +9,13 @@
 
 #include "base/macros.h"
 #include "components/arc/arc_bridge_service.h"
+#include "components/arc/arc_service.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace arc {
 
-class ArcClipboardBridge : public ArcBridgeService::Observer,
+class ArcClipboardBridge : public ArcService,
+                           public ArcBridgeService::Observer,
                            public ClipboardHost {
  public:
   explicit ArcClipboardBridge(ArcBridgeService* bridge_service);
@@ -29,8 +31,6 @@ class ArcClipboardBridge : public ArcBridgeService::Observer,
  private:
   bool CalledOnValidThread();
 
-  ArcBridgeService* bridge_service_;
-
   mojo::Binding<ClipboardHost> binding_;
 
   base::ThreadChecker thread_checker_;