Implementation for feature policy - fullscreen

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 11 matching lines @@
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #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"
 #include "core/events/Event.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/HostsUsingFeatures.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
 #include "core/html/HTMLIFrameElement.h"
@@ skipping 259 matching lines @@
   // Ignore this request if the document is not in a live frame.
   if (!document.isActive())
     return;
 
   // If |element| is on top of |doc|'s fullscreen element stack, terminate these
   // substeps.
   if (&element == fullscreenElementFrom(document))
     return;
 
   do {
+    Frame* frame = document.frame();

[foolip, 2016/11/28 23:33:22]

Making this part of fullscreenSupported should reduce code duplication. If you
need to make the argument non-const, that's fine.

Can you add a TODO to update the placement of the code once it's in
https://fullscreen.spec.whatwg.org/? (I assume that the plan for Feature Policy
is to eventually have each affected spec have the steps.)

[lunalu1, 2016/12/01 20:10:07]

Done.

+    DCHECK(frame->isLocalFrame());
+    if (!isFeatureEnabledInFrame(blink::kFullscreenFeature,
+                                 toLocalFrame(frame))) {
+      if (RuntimeEnabledFeatures::featurePolicyEnabled()) {
+        document.addConsoleMessage(ConsoleMessage::create(
+            JSMessageSource, WarningMessageLevel,
+            "Fullscreen API is not enabled in feature policy for this frame"));

[foolip, 2016/11/28 23:33:22]

Is this the wording used for other features? "Fullscreen API is disabled by
feature policy for this frame" would read slightly better I think.

[lunalu1, 2016/12/01 20:10:07]

Done.

+        break;
+      }
+    }
+
     // 1. If any of the following conditions are false, then terminate these
     // steps and queue a task to fire an event named fullscreenerror with its
     // bubbles attribute set to true on the context object's node document:
 
     // |element|'s namespace is the HTML namespace or |element| is an SVG
     // svg or MathML math element.
     // Note: MathML is not supported.
     if (!element.isHTMLElement() && !isSVGSVGElement(element))
       break;
 
@@ skipping 214 matching lines @@
     host->chromeClient().exitFullscreen(document.frame());
     return;
   }
 
   // Otherwise, notify the chrome of the new full screen element.
   host->chromeClient().enterFullscreenForElement(newTop);
 }
 
 // https://fullscreen.spec.whatwg.org/#dom-document-fullscreenenabled
 bool Fullscreen::fullscreenEnabled(Document& document) {
+  Frame* frame = document.frame();
+  if (!isFeatureEnabledInFrame(blink::kFullscreenFeature,
+                               toLocalFrame(frame))) {
+    if (RuntimeEnabledFeatures::featurePolicyEnabled()) {
+      document.addConsoleMessage(ConsoleMessage::create(
+          JSMessageSource, WarningMessageLevel,
+          "Fullscreen API is not enabled in feature policy for this frame"));
+      return false;
+    }
+  }
+
   // The fullscreenEnabled attribute's getter must return true if the context
   // object is allowed to use the feature indicated by attribute name
   // allowfullscreen and fullscreen is supported, and false otherwise.
-  return allowedToUseFullscreen(document.frame()) &&
-         fullscreenIsSupported(document);
+  if (!fullscreenIsSupported(document))
+    return false;
+
+  return allowedToUseFullscreen(frame);
 }
 
 void Fullscreen::didEnterFullscreenForElement(Element* element) {
   DCHECK(element);
   if (!document()->isActive())
     return;
 
   if (m_fullScreenLayoutObject)
     m_fullScreenLayoutObject->unwrapLayoutObject();
 
@@ skipping 202 matching lines @@
 
 DEFINE_TRACE(Fullscreen) {
   visitor->trace(m_currentFullScreenElement);
   visitor->trace(m_fullscreenElementStack);
   visitor->trace(m_eventQueue);
   Supplement<Document>::trace(visitor);
   ContextLifecycleObserver::trace(visitor);
 }
 
 }  // namespace blink