Revert of Makes the component installers return a Result instead of a bool.

chrome/browser/component_updater/ev_whitelist_component_installer.h

Index: chrome/browser/component_updater/ev_whitelist_component_installer.h
diff --git a/chrome/browser/component_updater/ev_whitelist_component_installer.h b/chrome/browser/component_updater/ev_whitelist_component_installer.h
index 33ee183cd5f708e63053e541d67414506dee2624..9e7c7b51c78182eb16fb012b8cdd37015ad0e784 100644
--- a/chrome/browser/component_updater/ev_whitelist_component_installer.h
+++ b/chrome/browser/component_updater/ev_whitelist_component_installer.h
@@ -32,9 +32,8 @@
   // The following methods override ComponentInstallerTraits.
   bool SupportsGroupPolicyEnabledComponentUpdates() const override;
   bool RequiresNetworkEncryption() const override;
-  update_client::CrxInstaller::Result OnCustomInstall(
-      const base::DictionaryValue& manifest,
-      const base::FilePath& install_dir) override;
+  bool OnCustomInstall(const base::DictionaryValue& manifest,
+                       const base::FilePath& install_dir) override;
   bool VerifyInstallation(const base::DictionaryValue& manifest,
                           const base::FilePath& install_dir) const override;
   void ComponentReady(const base::Version& version,