Adding WebVR interface to Blink

Source/modules/vr/HMDVRDevice.idl

+// 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.
+
+enum VREye {
+    "left",
+    "right"
+};
+
+// An HMDVRDevice represents a Head Mounted Display. The interface provides all
+// the information necessary to correctly render a stereo 3D scene for a given
+// headset.
+[
+    RuntimeEnabled=VRDevice,
+    TypeChecking=Interface
+] interface HMDVRDevice : VRDevice {
+    DOMPoint getEyeTranslation(VREye whichEye);
+    VRFieldOfView getCurrentEyeFieldOfView(VREye whichEye);
+    VRFieldOfView getRecommendedEyeFieldOfView(VREye whichEye);
+    VRFieldOfView getMaximumEyeFieldOfView(VREye whichEye);
+    DOMRect getRecommendedEyeRenderRect(VREye whichEye);
+    void setFieldOfView(optional VRFieldOfView leftFov, optional VRFieldOfView rightFov);
+};