Disable ExtensionApiTest.Wallpaper as it's flaky.

chrome/browser/chromeos/extensions/wallpaper_apitest.cc

Index: chrome/browser/chromeos/extensions/wallpaper_apitest.cc
diff --git a/chrome/browser/chromeos/extensions/wallpaper_apitest.cc b/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
index 66e69e511f818afc2ef89c1732bf78d1d9d3bc63..1e6a19dfaaca745f4a1bac7cfaecfb34e0c219c8 100644
--- a/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
+++ b/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
@@ -5,7 +5,8 @@
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "net/dns/mock_host_resolver.h"
 
-IN_PROC_BROWSER_TEST_F(ExtensionApiTest, Wallpaper) {
+// Disabled due to flakiness. See http://crbug.com/468632.
+IN_PROC_BROWSER_TEST_F(ExtensionApiTest, DISABLED_Wallpaper) {
   host_resolver()->AddRule("a.com", "127.0.0.1");
   ASSERT_TRUE(StartEmbeddedTestServer());
   ASSERT_TRUE(RunExtensionTest("wallpaper")) << message_;