Refactor VR math off of GVR types, onto gfx types where possible.

device/vr/android/gvr/gvr_delegate.h

Index: device/vr/android/gvr/gvr_delegate.h
diff --git a/device/vr/android/gvr/gvr_delegate.h b/device/vr/android/gvr/gvr_delegate.h
index 9a21aba076933b1ec072afeef6a4fde60308aa47..d51581937f073f0c0857e5f55f1d4986efbe4f48 100644
--- a/device/vr/android/gvr/gvr_delegate.h
+++ b/device/vr/android/gvr/gvr_delegate.h
@@ -9,30 +9,34 @@
 
 #include "device/vr/vr_export.h"
 #include "device/vr/vr_service.mojom.h"
+#include "device/vr/vr_types.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "third_party/gvr-android-sdk/src/libraries/headers/vr/gvr/capi/include/gvr_types.h"
 
+namespace gvr {
+class GvrApi;
+}
+
 namespace device {
 
 class DEVICE_VR_EXPORT GvrDelegate {
  public:
-  static mojom::VRPosePtr VRPosePtrFromGvrPose(gvr::Mat4f head_mat);
-  static gvr::Mat4f GetGvrPoseWithNeckModel(gvr::GvrApi* gvr_api);
+  static mojom::VRPosePtr VRPosePtrFromGvrPose(const vr::Mat4f& head_mat);
+  static void GetGvrPoseWithNeckModel(gvr::GvrApi* gvr_api, vr::Mat4f* out);
   static mojom::VRPosePtr GetVRPosePtrWithNeckModel(gvr::GvrApi* gvr_api,
-                                                    gvr::Mat4f* head_mat_out);
-  static gvr::Sizei GetRecommendedWebVrSize(gvr::GvrApi* gvr_api);
-  static mojom::VRDisplayInfoPtr CreateVRDisplayInfo(
-      gvr::GvrApi* gvr_api,
-      gvr::Sizei recommended_size,
-      uint32_t device_id);
+                                                    vr::Mat4f* head_mat_out);
+  static gfx::Size GetRecommendedWebVrSize(gvr::GvrApi* gvr_api);
+  static mojom::VRDisplayInfoPtr CreateVRDisplayInfo(gvr::GvrApi* gvr_api,
+                                                     gfx::Size recommended_size,
+                                                     uint32_t device_id);
 
   virtual void SetWebVRSecureOrigin(bool secure_origin) = 0;
   virtual void SubmitWebVRFrame(int16_t frame_index,
                                 const gpu::MailboxHolder& mailbox) = 0;
   virtual void UpdateWebVRTextureBounds(int16_t frame_index,
-                                        const gvr::Rectf& left_bounds,
-                                        const gvr::Rectf& right_bounds,
-                                        const gvr::Sizei& source_size) = 0;
+                                        const gfx::RectF& left_bounds,
+                                        const gfx::RectF& right_bounds,
+                                        const gfx::Size& source_size) = 0;
   virtual void OnVRVsyncProviderRequest(
       mojom::VRVSyncProviderRequest request) = 0;
   virtual void UpdateVSyncInterval(int64_t timebase_nanos,