ui: Cleanup class/struct forward declarations

chrome/browser/component_updater/pnacl_component_installer.h

Index: chrome/browser/component_updater/pnacl_component_installer.h
diff --git a/chrome/browser/component_updater/pnacl_component_installer.h b/chrome/browser/component_updater/pnacl_component_installer.h
index 5e44209c4ea2727540b62a970fa010404fdcb6a1..3f3981c382854f17f94d1c66aac1ec1655df1442 100644
--- a/chrome/browser/component_updater/pnacl_component_installer.h
+++ b/chrome/browser/component_updater/pnacl_component_installer.h
@@ -43,8 +43,9 @@ class PnaclComponentInstaller : public update_client::CrxInstaller {
 
   // ComponentInstaller implementation:
   void OnUpdateError(int error) override;
-  bool Install(const base::DictionaryValue& manifest,
-               const base::FilePath& unpack_path) override;
+  update_client::CrxInstaller::Result Install(
+      const base::DictionaryValue& manifest,
+      const base::FilePath& unpack_path) override;
   bool GetInstalledFile(const std::string& file,
                         base::FilePath* installed_file) override;
   bool Uninstall() override;
@@ -74,6 +75,9 @@ class PnaclComponentInstaller : public update_client::CrxInstaller {
  private:
   ~PnaclComponentInstaller() override;
 
+  bool DoInstall(const base::DictionaryValue& manifest,
+                 const base::FilePath& unpack_path);
+
   base::Version current_version_;
   std::string current_fingerprint_;
   ComponentUpdateService* cus_;