Disable MediaGalleriesPlatformAppBrowserTest.MediaGalleriesRead as its flaking.

chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc

Index: chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc
diff --git a/chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc b/chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc
index 367d890dd022182359dab0ae90e43a3ede03ffb7..56887eba3ecab7964b0fb9a9d2687986969e71cf 100644
--- a/chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc
+++ b/chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc
@@ -516,13 +516,8 @@ IN_PROC_BROWSER_TEST_F(MediaGalleriesPlatformAppBrowserTest,
 }
 
 // Test is flaky. crbug.com/416128
-#if defined(OS_MACOSX)
-#define MAYBE_MediaGalleriesRead DISABLED_MediaGalleriesRead
-#else
-#define MAYBE_MediaGalleriesRead MediaGalleriesRead
-#endif
 IN_PROC_BROWSER_TEST_F(MediaGalleriesPlatformAppBrowserTest,
-                       MAYBE_MediaGalleriesRead) {
+                       DISABLED_MediaGalleriesRead) {
   RemoveAllGalleries();
   MakeSingleFakeGallery(NULL);
   base::ListValue custom_args;