Implementation of elbow model for the controller position and rotation.

chrome/browser/android/vr_shell/vr_shell_gl.h

Index: chrome/browser/android/vr_shell/vr_shell_gl.h
diff --git a/chrome/browser/android/vr_shell/vr_shell_gl.h b/chrome/browser/android/vr_shell/vr_shell_gl.h
index 8aa1406723c3562c3da92109401f7173de305c47..f01c3b3bcfe18e7b85df8cbbc9ba18a4b7e494c1 100644
--- a/chrome/browser/android/vr_shell/vr_shell_gl.h
+++ b/chrome/browser/android/vr_shell/vr_shell_gl.h
@@ -130,8 +130,8 @@ class VrShellGl : public device::mojom::VRVSyncProvider {
   void DrawWebVr();
   bool WebVrPoseByteIsValid(int pose_index_byte);
 
-  void UpdateController();
-  void HandleControllerInput(const gfx::Vector3dF& forward_vector);
+  void UpdateController(const gfx::Vector3dF& head_direction);
+  void HandleControllerInput(const gfx::Vector3dF& head_direction);
   void HandleControllerAppButtonActivity(
       const gfx::Vector3dF& controller_direction);
   void SendEventsToTarget(InputTarget input_target, int pixel_x, int pixel_y);
@@ -232,6 +232,8 @@ class VrShellGl : public device::mojom::VRVSyncProvider {
 
   std::unique_ptr<FPSMeter> fps_meter_;
 
+  gfx::Point3F pointer_start_;
+
   base::WeakPtrFactory<VrShellGl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VrShellGl);