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..3aadf1a15312e05117666594b8ac649f464bf4ef 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_focused);
   m_displays.push_back(vrDisplay);
 
   if (m_displays.size() == m_numberOfSyncedDisplays) {
@@ -72,6 +73,12 @@ void VRController::OnDisplayConnected(
   }
 }
 
+void VRController::focusChanged(bool focused) {
+  m_focused = focused;
+  for (size_t i = 0; i < m_displays.size(); ++i)

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

super-nit: you could use a range-based loop here too:

for (const auto& display : m_displays)
  display->focusChanged(focused);

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

Done.

+    m_displays[i]->focusChanged(focused);
+}
+
 // Called when the VRService has called OnDisplayConnected for all active
 // VRDisplays.
 void VRController::onDisplaysSynced(unsigned numberOfDisplays) {