Provide WebVR pose data only to the focused frame.

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/vr/NavigatorVR.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/Document.h"
 #include "core/dom/DocumentUserGestureToken.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Navigator.h"
 #include "core/frame/UseCounter.h"
+#include "core/page/FocusController.h"
 #include "core/page/Page.h"
 #include "modules/vr/VRController.h"
 #include "modules/vr/VRDisplay.h"
 #include "modules/vr/VRGetDevicesCallback.h"
 #include "modules/vr/VRPose.h"
 #include "platform/UserGestureIndicator.h"
 #include "public/platform/Platform.h"
 #include "wtf/PtrUtil.h"
 
 namespace blink {
@@ skipping 43 matching lines @@
 
   return promise;
 }
 
 VRController* NavigatorVR::controller() {
   if (!supplementable()->frame())
     return 0;
 
   if (!m_controller) {
     m_controller = new VRController(this);
+    m_controller->setListeningForActivate(m_listeningForActivate);
+    m_controller->focusChanged(m_focused);
   }
 
   return m_controller;
 }
 
 Document* NavigatorVR::document() {
   return supplementable()->frame() ? supplementable()->frame()->document()
                                    : nullptr;
 }
 
 DEFINE_TRACE(NavigatorVR) {
   visitor->trace(m_controller);
   Supplement<Navigator>::trace(visitor);
-  PageVisibilityObserver::trace(visitor);
 }
 
 NavigatorVR::NavigatorVR(Navigator& navigator)
-    : Supplement<Navigator>(navigator),
-      PageVisibilityObserver(navigator.frame()->page()) {
+    : Supplement<Navigator>(navigator) {
   navigator.frame()->domWindow()->registerEventListenerObserver(this);
+  navigator.frame()->page()->focusController().registerFocusChangedObserver(
+      this);
+  focusedFrameChanged();
 }
 
 NavigatorVR::~NavigatorVR() {}
 
 const char* NavigatorVR::supplementName() {
   return "NavigatorVR";
 }
 
 void NavigatorVR::enqueueVREvent(VRDisplayEvent* event) {
   if (supplementable()->frame()) {
     supplementable()->frame()->domWindow()->enqueueWindowEvent(event);
   }
 }
 
 void NavigatorVR::dispatchVRGestureEvent(VRDisplayEvent* event) {
   if (!(supplementable()->frame()))
     return;
   UserGestureIndicator gestureIndicator(
       DocumentUserGestureToken::create(document()));
   LocalDOMWindow* window = supplementable()->frame()->domWindow();
   DCHECK(window);
   event->setTarget(window);
   window->dispatchEvent(event);
 }
 
-void NavigatorVR::pageVisibilityChanged() {
-  if (!page())
+void NavigatorVR::focusedFrameChanged() {

[jbroman, 2017/02/02 16:07:20]

nit: This condition might be clearer factored out to a static function?

static bool isFrameDocumentFocused(LocalFrame* frame) {
  if (!frame) return false;
  Page* page = frame->page();
  Document* document = frame->document();
  return page && document &&
page->focusController().isDocumentFocused(document);
}

void NavigatorVR::focusedFrameChanged() {
  const bool focused = supplementable() &&
isFrameDocumentFocused(supplementable()->frame());
  if (m_focused != focused && m_controller) {
    m_controller->setListeningForActivate(focused && m_listeningForActivate);
    m_controller->focusChanged(focused);
  }
  m_focused = focused;
}

[mthiesse, 2017/02/02 17:52:18]

Done.

+  if (supplementable() && supplementable()->frame() &&
+      supplementable()->frame()->page() &&
+      supplementable()->frame()->document() &&
+      supplementable()->frame()->page()->focusController().isDocumentFocused(

[jbroman, 2017/02/02 16:07:20]

Do you really want isDocumentFocused? This will return true if any descendant
frame has focus as well. This may or may not be what you want, but you probably
want to match whatever you'll implement on the browser side later on.

[mthiesse, 2017/02/02 17:52:18]

Hmm I think you're right, and isDocumentFocused was probably only working by
fluke since we only allow one VSync provider to be connected at a time.

+          *supplementable()->frame()->document())) {
+    if (!m_focused && m_controller) {
+      m_controller->setListeningForActivate(m_listeningForActivate);
+      m_controller->focusChanged(true);
+    }
+    m_focused = true;
     return;
-  if (m_controller) {
-    m_controller->setListeningForActivate(page()->isPageVisible() &&
-                                          m_listeningForActivate);
   }
+  if (m_focused && m_controller) {
+    m_controller->setListeningForActivate(false);
+    m_controller->focusChanged(false);
+  }
+  m_focused = false;
 }
 
 void NavigatorVR::didAddEventListener(LocalDOMWindow* window,
                                       const AtomicString& eventType) {
   if (eventType == EventTypeNames::vrdisplayactivate) {
-    controller()->setListeningForActivate(true);
+    controller()->setListeningForActivate(m_focused);
     m_listeningForActivate = true;
   } else if (eventType == EventTypeNames::vrdisplayconnect) {
     // If the page is listening for connection events make sure we've created a
     // controller so that we'll be notified of new devices.
     controller();
   }
 }
 
 void NavigatorVR::didRemoveEventListener(LocalDOMWindow* window,
                                          const AtomicString& eventType) {
   if (eventType == EventTypeNames::vrdisplayactivate &&
       !window->hasEventListeners(EventTypeNames::vrdisplayactivate)) {
     controller()->setListeningForActivate(false);
     m_listeningForActivate = false;
   }
 }
 
 void NavigatorVR::didRemoveAllEventListeners(LocalDOMWindow* window) {
   if (m_controller) {
     m_controller->setListeningForActivate(false);
     m_listeningForActivate = false;
   }
 }
 
 }  // namespace blink