Hold cros_component_installers in browser_process.

chrome/test/base/testing_browser_process.h

Index: chrome/test/base/testing_browser_process.h
diff --git a/chrome/test/base/testing_browser_process.h b/chrome/test/base/testing_browser_process.h
index 421de7e8900ee2b18bc28c73b49c9668dd3e77b1..813303e80727200927578afc3b0b4a458e091131 100644
--- a/chrome/test/base/testing_browser_process.h
+++ b/chrome/test/base/testing_browser_process.h
@@ -117,6 +117,13 @@ class TestingBrowserProcess : public BrowserProcess {
   CRLSetFetcher* crl_set_fetcher() override;
   component_updater::PnaclComponentInstaller* pnacl_component_installer()
       override;
+#if defined(OS_CHROMEOS)
+  component_updater::DefaultComponentInstaller* cros_component_installer(
+      const std::string& name,
+      std::unique_ptr<component_updater::ComponentInstallerTraits>
+          installer_traits) override;
+#endif
+
   component_updater::SupervisedUserWhitelistInstaller*
   supervised_user_whitelist_installer() override;
   MediaFileSystemRegistry* media_file_system_registry() override;