Enable Feature Policy without experimental features or 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 45 matching lines @@
 
 // https://html.spec.whatwg.org/multipage/embedded-content.html#allowed-to-use
 bool AllowedToUseFullscreen(const Frame* frame) {
   // To determine whether a Document object |document| is allowed to use the
   // feature indicated by attribute name |allowattribute|, run these steps:
 
   // 1. If |document| has no browsing context, then return false.
   if (!frame)
     return false;
 
+  // TODO(lunalu): Re-enable fullscreen in feature policy once all fullscreen

[iclelland, 2017/05/09 17:58:45]

As mentioned offline, I don't really like this, even for a temporary measure --
and it highlights the fact that we're still doing lots of tests inside the
calling code to see whether featurepolicy wants to handle a feature. Here it's
just if (RuntimeEnabledFeatures::featurePolicyEnabled()), but in vibrate code,
it's (RuntimeEnabledFeatures::featurePolicyEnabled() &&
RuntimeEnabledFeatures::featurePolicyExperimentalFeaturesEnabled()), and in
other code, it could be different, and change whenever we promote a feature from
experimental to stable.

Maybe the right thing to do is have a method in FeaturePolicy.cpp that says
whether FP is currently handling a given feature. Then we can centralize the
featurePolicyEnabled and featurePolicyExperimentalFeaturesEnabled logic, and put
the special case for Fullscreen right there. WDYT?

+  // tests have been re-written that "allowfullscreen" / "fullscreen" policy
+  // cannot be updated dynamically, by replacing the block below by commented
+  // block below.
+  // crbug.com/666761
+  // 2. If |document|'s browsing context is a top-level browsing context, then
+  // return true.
+  if (frame->IsMainFrame())
+    return true;
+
+  // 3. If |document|'s browsing context has a browsing context container that
+  // is an iframe element with an |allowattribute| attribute specified, and
+  // whose node document is allowed to use the feature indicated by
+  // |allowattribute|, then return true.
+  if (frame->Owner() && frame->Owner()->AllowFullscreen())
+    return AllowedToUseFullscreen(frame->Tree().Parent());
+
+  // 4. Return false.
+  return false;
+  /*
   if (!RuntimeEnabledFeatures::featurePolicyEnabled()) {
     // 2. If |document|'s browsing context is a top-level browsing context, then
     // return true.
     if (frame->IsMainFrame())
       return true;
 
     // 3. If |document|'s browsing context has a browsing context container that
     // is an iframe element with an |allowattribute| attribute specified, and
     // whose node document is allowed to use the feature indicated by
     // |allowattribute|, then return true.
     if (frame->Owner() && frame->Owner()->AllowFullscreen())
       return AllowedToUseFullscreen(frame->Tree().Parent());
 
     // 4. Return false.
     return false;
   }
 
   // 2. If Feature Policy is enabled, return the policy for "fullscreen"
   // feature.
   return frame->IsFeatureEnabled(WebFeaturePolicyFeature::kFullscreen);
+  */
 }
 
 bool AllowedToRequestFullscreen(Document& document) {
   // An algorithm is allowed to request fullscreen if one of the following is
   // true:
 
   //  The algorithm is triggered by a user activation.
   if (UserGestureIndicator::ProcessingUserGesture())
     return true;
 
@@ skipping 751 matching lines @@
 DEFINE_TRACE(Fullscreen) {
   visitor->Trace(pending_fullscreen_element_);
   visitor->Trace(fullscreen_element_stack_);
   visitor->Trace(current_full_screen_element_);
   visitor->Trace(event_queue_);
   Supplement<Document>::Trace(visitor);
   ContextLifecycleObserver::Trace(visitor);
 }
 
 }  // namespace blink