Disable NewlibPackagedAppTest.SuccessfulLoad

Disabling flaky test on mac

TBR=bbudge@chromium.org

BUG=707068

Change-Id: Ib401bfa6ef15e336fdcbe6ae231b97ec7c6cfdd9
Reviewed-on: https://chromium-review.googlesource.com/1112890Reviewed-by: Darren Shen <shend@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569946}

chrome/test/ppapi/ppapi_browsertest.cc

@@ -1326,7 +1326,7 @@ class NonSfiPackagedAppTest : public PackagedAppTest {
 
 // Load a packaged app, and wait for it to successfully post a "hello" message
 // back.
-#if defined(OS_WIN) || !defined(NDEBUG)
+#if defined(OS_WIN) || !defined(NDEBUG) || defined(OS_MACOSX)
 // flaky: crbug.com/707068
 // flaky on debug builds: crbug.com/709447
 IN_PROC_BROWSER_TEST_F(NewlibPackagedAppTest, DISABLED_SuccessfulLoad) {