Disable the image notification property on MacOS

third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5

Index: third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
diff --git a/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5 b/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
index 82898e6ee6ab1e2580960b3c5518d76f22730096..4d917199aa5364eee2e1a7a10a4be83463bbf176 100644
--- a/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
+++ b/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
@@ -651,9 +651,10 @@
       name: "NotificationConstructor",
       status: "stable",
     },
+    // NotificationContentImage is not available in all platforms
     {
       name: "NotificationContentImage",
-      status: "stable",
+      status: "test",

[foolip, 2017/04/13 08:38:12]

Can you keep status "stable" and disable it on Mac instead? When trying to
figure out which parts of our IDL we are actually shipping, i.e. where it's
important that it matches the spec, it's a problem if it looks like a feature
isn't shipping but actually is. There are some cases, but the fewer the better.

     },
     {
       name: "NotificationInlineReplies",