Added allowvr attribute to iframes and vrEnabled to Document

third_party/WebKit/Source/modules/vr/NavigatorVR.cpp

Index: third_party/WebKit/Source/modules/vr/NavigatorVR.cpp
diff --git a/third_party/WebKit/Source/modules/vr/NavigatorVR.cpp b/third_party/WebKit/Source/modules/vr/NavigatorVR.cpp
index b3acb36935316dd79addae9993ee094dfba11e3a..4a4ef3789d5d1c98fda4a1b1f6918bc7b22535a7 100644
--- a/third_party/WebKit/Source/modules/vr/NavigatorVR.cpp
+++ b/third_party/WebKit/Source/modules/vr/NavigatorVR.cpp
@@ -8,6 +8,7 @@
 #include "core/dom/DOMException.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/frame/FrameOwner.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Navigator.h"
@@ -20,6 +21,32 @@
 
 namespace blink {
 
+// https://html.spec.whatwg.org/multipage/embedded-content.html#allowed-to-use
+bool NavigatorVR::allowedToUseVR(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;
+
+    // 2. If |document|'s browsing context has no browsing context container, 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()->allowVR())
+        return allowedToUseVR(frame->tree().parent());
+
+    // 4. Return false.
+    return false;
+}
+
 NavigatorVR* NavigatorVR::from(Document& document)
 {
     if (!document.frame() || !document.frame()->domWindow())
@@ -48,6 +75,12 @@ ScriptPromise NavigatorVR::getVRDisplays(ScriptState* scriptState)
     ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
 
+    if (!allowedToUseVR(m_frame)) {
+        DOMException* exception = DOMException::create(NotAllowedError, "Access to VR devices is not allowed in this context.");
+        resolver->reject(exception);
+        return promise;
+    }
+
     Document* document = m_frame ? m_frame->document() : 0;
 
     if (!document || !controller()) {