Implementation for feature policy - fullscreen

third_party/WebKit/Source/core/dom/Fullscreen.cpp

Index: third_party/WebKit/Source/core/dom/Fullscreen.cpp
diff --git a/third_party/WebKit/Source/core/dom/Fullscreen.cpp b/third_party/WebKit/Source/core/dom/Fullscreen.cpp
index ff1331bd4cadc423dc311e1626746ce7ce733867..dd02115baf9a0c17b99f816597ac0b31d68c039b 100644
--- a/third_party/WebKit/Source/core/dom/Fullscreen.cpp
+++ b/third_party/WebKit/Source/core/dom/Fullscreen.cpp
@@ -29,6 +29,7 @@
 
 #include "core/dom/Fullscreen.h"
 
+#include "bindings/core/v8/ConditionalFeatures.h"
 #include "core/dom/Document.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/StyleEngine.h"
@@ -100,7 +101,21 @@ bool allowedToRequestFullscreen(Document& document) {
 }
 
 // https://fullscreen.spec.whatwg.org/#fullscreen-is-supported
-bool fullscreenIsSupported(const Document& document) {
+// TODO(lunalu): update the placement of the feature policy code once it is in
+// https://fullscreen.spec.whatwg.org/.
+bool fullscreenIsSupported(Document& document) {
+  LocalFrame* frame = document.frame();
+  if (!frame)
+    return false;
+
+  if (!isFeatureEnabledInFrame(blink::kFullscreenFeature, frame)) {
+    if (RuntimeEnabledFeatures::featurePolicyEnabled()) {
+      document.addConsoleMessage(ConsoleMessage::create(
+          JSMessageSource, WarningMessageLevel,
+          "Fullscreen API is disabled by feature policy for this frame"));
+      return false;
+    }
+  }
   // Fullscreen is supported if there is no previously-established user
   // preference, security risk, or platform limitation.
   return !document.settings() || document.settings()->fullscreenSupported();