Disable some extensions_unittests on LSAN builds.

extensions/renderer/mojo/stash_client_unittest.cc

Index: extensions/renderer/mojo/stash_client_unittest.cc
diff --git a/extensions/renderer/mojo/stash_client_unittest.cc b/extensions/renderer/mojo/stash_client_unittest.cc
index cddd20d5b560d1830710b09683d9e3ec72e9d3ec..3f361cc253582fa76a47d6304bf5113c0dff6702 100644
--- a/extensions/renderer/mojo/stash_client_unittest.cc
+++ b/extensions/renderer/mojo/stash_client_unittest.cc
@@ -37,8 +37,14 @@ class StashClientTest : public ApiTestBase {
   DISALLOW_COPY_AND_ASSIGN(StashClientTest);
 };
 
+// https://crbug.com/599898
+#if defined(LEAK_SANITIZER)
+#define MAYBE_StashAndRestore DISABLED_StashAndRestore
+#else
+#define MAYBE_StashAndRestore StashAndRestore
+#endif
 // Test that stashing and restoring work correctly.
-TEST_F(StashClientTest, StashAndRestore) {
+TEST_F(StashClientTest, MAYBE_StashAndRestore) {
   ASSERT_NO_FATAL_FAILURE(RunTest("stash_client_unittest.js", "testStash"));
   scoped_ptr<ModuleSystemTestEnvironment> restore_test_env(CreateEnvironment());
   ApiTestEnvironment restore_environment(restore_test_env.get());