Update ExtensionInstallChecker to use PreloadCheck classes

chrome/browser/extensions/crx_installer.h

Index: chrome/browser/extensions/crx_installer.h
diff --git a/chrome/browser/extensions/crx_installer.h b/chrome/browser/extensions/crx_installer.h
index e16d57cce649cf0ba724140a37bb07512d56e4e6..9f73dd36b434622c3620dcd8116354154c67b15d 100644
--- a/chrome/browser/extensions/crx_installer.h
+++ b/chrome/browser/extensions/crx_installer.h
@@ -243,10 +243,6 @@ class CrxInstaller : public SandboxedUnpackerClient {
   // Runs on the UI thread. Callback from ExtensionInstallChecker.
   void OnInstallChecksComplete(int failed_checks);
 
-  // Runs on the UI thread. Callback from Blacklist.
-  void OnBlacklistChecked(
-      extensions::BlacklistState blacklist_state);
-
   // Runs on the UI thread. Confirms the installation to the ExtensionService.
   void ConfirmInstall();