[Sync] Replace manual DI with SetTestingFactory.

chrome/browser/ui/webui/sync_internals_message_handler.h

Index: chrome/browser/ui/webui/sync_internals_message_handler.h
diff --git a/chrome/browser/ui/webui/sync_internals_message_handler.h b/chrome/browser/ui/webui/sync_internals_message_handler.h
index 2ef1840b073e0c6e7243e0868780ea22d8410aa0..fa703cfa35a42582578d4f13e2b0059ae7fe3fe4 100644
--- a/chrome/browser/ui/webui/sync_internals_message_handler.h
+++ b/chrome/browser/ui/webui/sync_internals_message_handler.h
@@ -96,16 +96,14 @@ class SyncInternalsMessageHandler : public content::WebUIMessageHandler,
                          std::unique_ptr<base::DictionaryValue> value);
 
  protected:
-  using SyncServiceProvider = base::RepeatingCallback<syncer::SyncService*()>;
-
   using AboutSyncDataDelegate =
       base::RepeatingCallback<std::unique_ptr<base::DictionaryValue>(
           syncer::SyncService* service,
           version_info::Channel channel)>;
 
   // Constructor used for unit testing to override dependencies.
-  SyncInternalsMessageHandler(SyncServiceProvider sync_service_provider,
-                              AboutSyncDataDelegate about_sync_data_delegate);
+  explicit SyncInternalsMessageHandler(
+      AboutSyncDataDelegate about_sync_data_delegate);
 
  private:
   // Fetches updated aboutInfo and sends it to the page in the form of an
@@ -113,9 +111,8 @@ class SyncInternalsMessageHandler : public content::WebUIMessageHandler,
   void SendAboutInfo();
 
   // Gets the ProfileSyncService of the underlying original profile. May return
-  // nullptr (e.g., if sync is disabled on the command line). Shouldn't be
-  // called directly, but instead through |sync_service_provider_|.
-  syncer::SyncService* BindForSyncServiceProvider();
+  // nullptr (e.g., if sync is disabled on the command line).
+  syncer::SyncService* GetSyncService();
 
   // Sends a dispatch event to the UI. Javascript must be enabled.
   void DispatchEvent(const std::string& name, const base::Value& details_value);
@@ -133,9 +130,6 @@ class SyncInternalsMessageHandler : public content::WebUIMessageHandler,
   // ProfileSyncService.
   bool is_registered_for_counters_ = false;
 
-  // An abstraction of who provides the SyncService.
-  SyncServiceProvider sync_service_provider_;
-
   // An abstraction of who creates the about sync info value map.
   AboutSyncDataDelegate about_sync_data_delegate_;