Enable scrolling of UI elements.

chrome/browser/android/vr_shell/vr_shell_gl.h

 // Copyright 2016 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.
 
 #ifndef CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_
 
 #include <memory>
 #include <queue>
 #include <utility>
@@ skipping 148 matching lines @@
   gvr::Sizei render_size_headlocked_;
 
   std::unique_ptr<VrShellRenderer> vr_shell_renderer_;
 
   bool touch_pending_ = false;
   gvr::Quatf controller_quat_;
 
   gvr::Vec3f target_point_;
   const ContentRectangle* target_element_ = nullptr;
   InputTarget current_input_target_ = InputTarget::NONE;
+  InputTarget current_scroll_target = InputTarget::NONE;
   int ui_tex_css_width_ = 0;
   int ui_tex_css_height_ = 0;
   int content_tex_css_width_ = 0;
   int content_tex_css_height_ = 0;
   gvr::Sizei content_tex_physical_size_ = {0, 0};
   gvr::Sizei ui_tex_physical_size_ = {0, 0};
 
   std::vector<gvr::Mat4f> webvr_head_pose_;
   int webvr_texture_id_ = 0;
   bool web_vr_mode_;
@@ skipping 22 matching lines @@
   uint16_t last_frame_index_ = -1;
 
   base::WeakPtrFactory<VrShellGl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VrShellGl);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_SHELL_GL_H_