Fix WebVR so we don't animation when stopped at a JS breakpoint

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

Index: third_party/WebKit/Source/modules/vr/VRDisplay.cpp
diff --git a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
index ace724eec6f9ca1ef506f130936aee361715a9f3..fd94a9c7851f776217acf3ed07c0e7292a9cfba6 100644
--- a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
+++ b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
@@ -55,17 +55,30 @@ VREye StringToVREye(const String& which_eye) {
 VRDisplay::VRDisplay(NavigatorVR* navigator_vr,
                      device::mojom::blink::VRDisplayPtr display,
                      device::mojom::blink::VRDisplayClientRequest request)
-    : ContextLifecycleObserver(navigator_vr->GetDocument()),
+    : SuspendableObject(navigator_vr->GetDocument()),
       navigator_vr_(navigator_vr),
       capabilities_(new VRDisplayCapabilities()),
       eye_parameters_left_(new VREyeParameters()),
       eye_parameters_right_(new VREyeParameters()),
       display_(std::move(display)),
       submit_frame_client_binding_(this),
-      display_client_binding_(this, std::move(request)) {}
+      display_client_binding_(this, std::move(request)) {
+  SuspendIfNeeded();  // Initialize suspended_.
+}
 
 VRDisplay::~VRDisplay() {}
 
+void VRDisplay::Suspend() {
+  suspended_ = true;
+}
+
+void VRDisplay::Resume() {
+  suspended_ = false;
+  if (request_vsync_on_resume_) {

[mthiesse, 2017/06/08 03:26:30]

No need for this boolean. RequestVSync() is always safe to call, and returns
early if you shouldn't schedule the vsync.

[billorr, 2017/06/08 04:20:21]

Done.

+    RequestVSync();
+  }
+}
+
 VRController* VRDisplay::Controller() {
   return navigator_vr_->Controller();
 }
@@ -801,6 +814,13 @@ void VRDisplay::ProcessScheduledAnimations(double timestamp) {
     return;
   }
 
+  if (suspended_) {
+    // We are currently suspended - try ProcessScheduledAnimations again later
+    // when we resume.
+    request_vsync_on_resume_ = true;
+    return;
+  }
+
   TRACE_EVENT1("gpu", "VRDisplay::OnVSync", "frame", vr_frame_id_);
 
   if (pending_vrdisplay_raf_ && scripted_animation_controller_) {
@@ -910,7 +930,8 @@ const AtomicString& VRDisplay::InterfaceName() const {
   return EventTargetNames::VRDisplay;
 }
 
-void VRDisplay::ContextDestroyed(ExecutionContext*) {
+void VRDisplay::ContextDestroyed(ExecutionContext* context) {
+  SuspendableObject::ContextDestroyed(context);
   ForceExitPresent();
   scripted_animation_controller_.Clear();
 }