Turn FaviconClient into a Keyed service.

components/favicon/core/browser/favicon_client.h

Index: components/favicon/core/browser/favicon_client.h
diff --git a/components/favicon/core/browser/favicon_client.h b/components/favicon/core/browser/favicon_client.h
index 34cb815b2767a0f3eb7bedab2866e8a57d4029fd..f33d54a028d02e44a3c120a8c4f1bb76c09f18ca 100644
--- a/components/favicon/core/browser/favicon_client.h
+++ b/components/favicon/core/browser/favicon_client.h
@@ -5,12 +5,14 @@
 #ifndef COMPONENTS_FAVICON_CORE_BROWSER_FAVICON_CLIENT_H_
 #define COMPONENTS_FAVICON_CORE_BROWSER_FAVICON_CLIENT_H_
 
+#include "components/keyed_service/core/keyed_service.h"
+
 class FaviconService;
 class GURL;
 
 // This class abstracts operations that depend on the embedder's environment,
 // e.g. Chrome.
-class FaviconClient {
+class FaviconClient : public KeyedService {
  public:
   virtual ~FaviconClient() {};