Turn off SessionStorageContextMojoTest.StartupShutdownSave

Test is flaky.

Bug: 1006416
Change-Id: I7395e93b95572708c110e7bdd57bc154d552c687
TBR: dmurph@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1832246Reviewed-by: Frank Liberato <liberato@chromium.org>
Commit-Queue: Frank Liberato <liberato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701235}

content/browser/dom_storage/session_storage_context_mojo_unittest.cc

@@ -243,7 +243,7 @@ TEST_F(SessionStorageContextMojoTest, MigrationV0ToV1) {
                                key_as_vector, String16ToUint8Vector(value))));
 }
 
-TEST_F(SessionStorageContextMojoTest, StartupShutdownSave) {
+TEST_F(SessionStorageContextMojoTest, DISABLED_StartupShutdownSave) {
   std::string namespace_id1 = base::GenerateGUID();
   url::Origin origin1 = url::Origin::Create(GURL("http://foobar.com"));
   context()->CreateSessionNamespace(namespace_id1);