Disable flaky test: ProcessProxyTest.RegistryNotifiedOnProcessExit

TBR=tbarzic@chromium.org

No-Try: true
Bug: 1151205
Change-Id: Id39eb0bf84373073db454ba94c0d76c006b12b1a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2551884Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829581}

chromeos/process_proxy/process_proxy_unittest.cc

@@ -275,7 +275,9 @@ TEST_F(ProcessProxyTest, RegistryTest) {
 }
 
 // Open new process, then kill it. Verifiy that we detect when the process dies.
-TEST_F(ProcessProxyTest, RegistryNotifiedOnProcessExit) {
+//
+// Disabled due to flakiness: https://crbug.com/1151205
+TEST_F(ProcessProxyTest, DISABLED_RegistryNotifiedOnProcessExit) {
   test_runner_.reset(new RegistryNotifiedOnProcessExitTestRunner());
   RunTest();
 }