Split the private webstore install API into two parts....

chrome/browser/extensions/extension_gallery_install_apitest.cc

Index: chrome/browser/extensions/extension_gallery_install_apitest.cc
===================================================================
--- chrome/browser/extensions/extension_gallery_install_apitest.cc	(revision 65457)
+++ chrome/browser/extensions/extension_gallery_install_apitest.cc	(working copy)
@@ -33,11 +33,18 @@
       "http://www.example.com:%u/files/extensions/",
       test_server()->host_port_pair().port());
 
+  BeginInstallFunction::SetIgnoreUserGestureForTests(true);
   std::string testing_install_base_url = base_url;
   testing_install_base_url += "good.crx";
-  InstallFunction::SetTestingInstallBaseUrl(testing_install_base_url.c_str());
+  CompleteInstallFunction::SetTestingInstallBaseUrl(
+      testing_install_base_url.c_str());
 
   std::string page_url = base_url;
   page_url += "api_test/extension_gallery_install/test.html";
   ASSERT_TRUE(RunPageTest(page_url.c_str()));
+
+  page_url = base_url;
+  page_url += "api_test/extension_gallery_install/test.html?expect_error=true";
+  BeginInstallFunction::SetIgnoreUserGestureForTests(false);
+  ASSERT_TRUE(RunPageTest(page_url.c_str()));
 }