Split FaviconService and FaviconServiceImpl.

ios/chrome/browser/favicon/favicon_service_factory.cc

Index: ios/chrome/browser/favicon/favicon_service_factory.cc
diff --git a/ios/chrome/browser/favicon/favicon_service_factory.cc b/ios/chrome/browser/favicon/favicon_service_factory.cc
index 0c72fd5137fd740c757d1db9aa1a45d7c2ef8c47..9db205129eb71c641a51dae1e6d981bdb07ed6c6 100644
--- a/ios/chrome/browser/favicon/favicon_service_factory.cc
+++ b/ios/chrome/browser/favicon/favicon_service_factory.cc
@@ -6,7 +6,7 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/memory/singleton.h"
-#include "components/favicon/core/favicon_service.h"
+#include "components/favicon/core/favicon_service_impl.h"
 #include "components/keyed_service/core/service_access_type.h"
 #include "components/keyed_service/ios/browser_state_dependency_manager.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
@@ -52,7 +52,7 @@ std::unique_ptr<KeyedService> FaviconServiceFactory::BuildServiceInstanceFor(
     web::BrowserState* context) const {
   ios::ChromeBrowserState* browser_state =
       ios::ChromeBrowserState::FromBrowserState(context);
-  return base::MakeUnique<favicon::FaviconService>(
+  return base::MakeUnique<favicon::FaviconServiceImpl>(
       base::MakeUnique<FaviconClientImpl>(),
       ios::HistoryServiceFactory::GetForBrowserState(
           browser_state, ServiceAccessType::EXPLICIT_ACCESS));