Provide WebVR pose data only to the focused frame.

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

Index: third_party/WebKit/Source/modules/vr/VRController.cpp
diff --git a/third_party/WebKit/Source/modules/vr/VRController.cpp b/third_party/WebKit/Source/modules/vr/VRController.cpp
index 0df41d123929b8776bdb9a749274202c3f2677af..028834ba218097cc143015c0104c078f9910326c 100644
--- a/third_party/WebKit/Source/modules/vr/VRController.cpp
+++ b/third_party/WebKit/Source/modules/vr/VRController.cpp
@@ -64,6 +64,7 @@ void VRController::OnDisplayConnected(
       new VRDisplay(m_navigatorVR, std::move(display), std::move(request));
   vrDisplay->update(displayInfo);
   vrDisplay->onConnected();
+  vrDisplay->focusChanged();
   m_displays.push_back(vrDisplay);
 
   if (m_displays.size() == m_numberOfSyncedDisplays) {
@@ -72,6 +73,11 @@ void VRController::OnDisplayConnected(
   }
 }
 
+void VRController::focusChanged() {
+  for (const auto& display : m_displays)
+    display->focusChanged();
+}
+
 // Called when the VRService has called OnDisplayConnected for all active
 // VRDisplays.
 void VRController::onDisplaysSynced(unsigned numberOfDisplays) {
@@ -101,8 +107,8 @@ void VRController::dispose() {
   m_binding.Close();
 
   // Shutdown all displays' message pipe
-  for (size_t i = 0; i < m_displays.size(); ++i)
-    m_displays[i]->dispose();
+  for (const auto& display : m_displays)
+    display->dispose();
 
   m_displays.clear();