Send LayerSquashing back to test mode.

TBR=abarth
BUG=382129

Review URL: https://codereview.chromium.org/323853007

git-svn-id: svn://svn.chromium.org/blink/trunk@175825 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in

@@ -70,7 +70,7 @@ ImageDataConstructor status=experimental
 IndexedDBExperimental status=experimental
 InputModeAttribute status=experimental
 LangAttributeAwareFormControlUI
-LayerSquashing status=stable
+LayerSquashing status=test
 PrefixedEncryptedMedia status=stable
 LocalStorage status=stable
 Manifest status=test