Implement an observer for the component updater.

chrome/browser/component_updater/test/update_checker_unittest.cc

Index: chrome/browser/component_updater/test/update_checker_unittest.cc
diff --git a/chrome/browser/component_updater/test/update_checker_unittest.cc b/chrome/browser/component_updater/test/update_checker_unittest.cc
index 117caf3900e82647bb0e62377d4d359bbb5d0327..09c2b3f3c249609d7ef5d502e048c4395418484f 100644
--- a/chrome/browser/component_updater/test/update_checker_unittest.cc
+++ b/chrome/browser/component_updater/test/update_checker_unittest.cc
@@ -149,7 +149,6 @@ CrxUpdateItem UpdateCheckerTest::BuildCrxUpdateItem() {
   crx_component.name = "test_jebg";
   crx_component.pk_hash.assign(jebg_hash, jebg_hash + arraysize(jebg_hash));
   crx_component.installer = NULL;
-  crx_component.observer = NULL;
   crx_component.version = base::Version("0.9");
   crx_component.fingerprint = "fp1";