WebVR: Update VRDisplay.GetFrameData to follow the current spec.

The WebVR 1.1 spec was updated to clarify the behavior of getFrameData. Now, GetFrameData should return false unless called within a VRDisplay.requestAnimationFrame callback. BUG=736023 Change-Id: I14d9442a016817a78232ed7b1e71956c8dac614a Reviewed-on: https://chromium-review.googlesource.com/578188Reviewed-by: Brandon Jones <bajones@chromium.org> Commit-Queue: Bill Orr <billorr@chromium.org> Cr-Commit-Position: refs/heads/master@{#487970}

WebVR: Update VRDisplay.GetFrameData to follow the current spec.
The WebVR 1.1 spec was updated to clarify the behavior of getFrameData. Now, GetFrameData should return false unless called within a VRDisplay.requestAnimationFrame callback. BUG=736023 Change-Id: I14d9442a016817a78232ed7b1e71956c8dac614a Reviewed-on: https://chromium-review.googlesource.com/578188Reviewed-by: Brandon Jones <bajones@chromium.org> Commit-Queue: Bill Orr <billorr@chromium.org> Cr-Commit-Position: refs/heads/master@{#487970}
14020f57 · Bill Orr · Commit Bot · b54ae338 · 14020f57 · 14020f57
Commit 14020f57 authored Jul 19, 2017 by Bill Orr Committed by Commit Bot Jul 19, 2017
2 changed files
--- a/third_party/WebKit/LayoutTests/vr/getFrameData_windowRAF.html
+++ b/third_party/WebKit/LayoutTests/vr/getFrameData_windowRAF.html
+<!DOCTYPE html>
+<script src="../resources/testharness.js"></script>
+<script src="../resources/testharnessreport.js"></script>
+<script src="resources/fake-vr-displays.js"></script>
+<script src="file:///gen/layout_test_data/mojo/public/js/mojo_bindings.js"></script>
+<script src="file:///gen/device/vr/vr_service.mojom.js"></script>
+<script src="resources/mock-vr-service.js"></script>
+<script src="resources/test-constants.js"></script>
+<script>
+let fakeDisplays = fakeVRDisplays();
+
+vr_test( (t, mock_service) => {
+  return navigator.getVRDisplays().then( (displays) => {
+    var display = displays[0];
+    var expected_pose = VALID_POSE;
+    var fd = new VRFrameData();
+    var counter = 0;
+
+    function onFrame() {
+      window.requestAnimationFrame(onFrame);
+      if (counter == 0) {
+        t.step( () => {
+          assert_false(display.getFrameData(fd));
+        }, "Expecting to not get framedata since there is no pose");
+        mock_service.mockVRDisplays_[0].setPose(expected_pose);
+        t.step( () => {
+          assert_false(display.getFrameData(fd));
+        }, "Does not update within the same frame");
+      } else {
+        t.step( () => {
+          assert_false(display.getFrameData(fd));
+        }, "getFrameData is expected to return false when not in a display RAF callback");
+        t.done();
+      }
+      counter++;
+    }
+
+    window.requestAnimationFrame(onFrame);
+  }, (err) => {
+    t.step( () => {
+      assert_unreached("getVRDisplays rejected");
+    });
+  });
+}, [fakeDisplays["Pixel"]],
+"getFrameData updates on the next frame");
+
+</script>
--- a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
+++ b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
@@ -148,6 +148,17 @@ bool VRDisplay::getFrameData(VRFrameData* frame_data) {
  if (!frame_data)
    return false;

+  if (!in_animation_frame_) {
+    Document* doc = navigator_vr_->GetDocument();
+    if (doc) {
+      doc->AddConsoleMessage(
+          ConsoleMessage::Create(kRenderingMessageSource, kWarningMessageLevel,
+                                 "getFrameData must be called within a "
+                                 "VRDisplay.requestAnimationFrame callback."));
+    }
+    return false;
+  }
+
  if (depth_near_ == depth_far_)
    return false;