Add tests for exiting from nested fullscreen

third_party/WebKit/LayoutTests/external/wpt/MANIFEST.json

Index: third_party/WebKit/LayoutTests/external/wpt/MANIFEST.json
diff --git a/third_party/WebKit/LayoutTests/external/wpt/MANIFEST.json b/third_party/WebKit/LayoutTests/external/wpt/MANIFEST.json
index fa54c7f73d2200f05bfc820cc3e91ab777f0c38e..edc05b1b568946e3f075bcf4b03a3e29091df133 100644
--- a/third_party/WebKit/LayoutTests/external/wpt/MANIFEST.json
+++ b/third_party/WebKit/LayoutTests/external/wpt/MANIFEST.json
@@ -13,6 +13,18 @@
      {}
     ]
    ],
+   "fullscreen/api/document-exit-fullscreen-nested-in-iframe-manual.html": [
+    [
+     "/fullscreen/api/document-exit-fullscreen-nested-in-iframe-manual.html",
+     {}
+    ]
+   ],
+   "fullscreen/api/document-exit-fullscreen-nested-manual.html": [
+    [
+     "/fullscreen/api/document-exit-fullscreen-nested-manual.html",
+     {}
+    ]
+   ],
    "fullscreen/api/document-exit-fullscreen-timing-manual.html": [
     [
      "/fullscreen/api/document-exit-fullscreen-timing-manual.html",
@@ -61278,6 +61290,14 @@
    "673d72414fab3dbb677d21a05008d9014daf71bf",
    "manual"
   ],
+  "fullscreen/api/document-exit-fullscreen-nested-in-iframe-manual.html": [
+   "521f776f725c48e6f38bd8af3e6bff498c8ea604",
+   "manual"
+  ],
+  "fullscreen/api/document-exit-fullscreen-nested-manual.html": [
+   "5ddaf5fd8c2aef02fc4cefffa80a569e513a5491",
+   "manual"
+  ],
   "fullscreen/api/document-exit-fullscreen-timing-manual-expected.txt": [
    "bb2508e35e8e52593e6fc4282f17c186f31e6bd3",
    "support"
@@ -69951,7 +69971,7 @@
    "testharness"
   ],
   "html/semantics/embedded-content/the-iframe-element/iframe_sandbox_allow_top_navigation_by_user_activation-manual.html": [
-   "ffed01db4e8c7b2bb566dc1f0d1108e35255be19",
+   "31fa1d1e2ad26e0e6746269a4f7673c2e12c187f",
    "manual"
   ],
   "html/semantics/embedded-content/the-iframe-element/iframe_sandbox_allow_top_navigation_by_user_activation_without_user_gesture.html": [
@@ -70011,7 +70031,7 @@
    "support"
   ],
   "html/semantics/embedded-content/the-iframe-element/support/iframe-that-performs-top-navigation.html": [
-   "b380676429cf167a475c07dc549945052cf4bc21",
+   "1fb30b9d76157dc9f5ac9d294cec54c2d9479a9d",
    "support"
   ],
   "html/semantics/embedded-content/the-iframe-element/support/navigation-changed-iframe.html": [