Add support for uninstalling components and use it in SupervisedUserWhitelistInstaller.

chrome/browser/component_updater/pepper_flash_component_installer.cc

Index: chrome/browser/component_updater/pepper_flash_component_installer.cc
diff --git a/chrome/browser/component_updater/pepper_flash_component_installer.cc b/chrome/browser/component_updater/pepper_flash_component_installer.cc
index e811a995cf4e53533579dddf0a7c27b7dc64bae8..485a758965ebdf046fde0694d668d46aa81c1833 100644
--- a/chrome/browser/component_updater/pepper_flash_component_installer.cc
+++ b/chrome/browser/component_updater/pepper_flash_component_installer.cc
@@ -344,6 +344,8 @@ class PepperFlashComponentInstaller : public update_client::ComponentInstaller {
   bool GetInstalledFile(const std::string& file,
                         base::FilePath* installed_file) override;
 
+  bool Uninstall() override;
+
  private:
   ~PepperFlashComponentInstaller() override {}
 
@@ -395,6 +397,10 @@ bool PepperFlashComponentInstaller::GetInstalledFile(
   return false;
 }
 
+bool PepperFlashComponentInstaller::Uninstall() {
+  return false;
+}
+
 bool CheckPepperFlashManifest(const base::DictionaryValue& manifest,
                               Version* version_out) {
   std::string name;