Introduce ViewRoot forwarding input/view events to native

chrome/browser/android/vr_shell/vr_shell.h

Index: chrome/browser/android/vr_shell/vr_shell.h
diff --git a/chrome/browser/android/vr_shell/vr_shell.h b/chrome/browser/android/vr_shell/vr_shell.h
index 8b71dc0289b666053f80d3ee30d8fe4fab5567ca..74d491de4c725f4f7d34d548e654cfb24cfacc59 100644
--- a/chrome/browser/android/vr_shell/vr_shell.h
+++ b/chrome/browser/android/vr_shell/vr_shell.h
@@ -29,7 +29,7 @@ class WebContents;
 }
 
 namespace ui {
-class WindowAndroid;
+class ViewRoot;
 }
 
 namespace vr_shell {
@@ -58,9 +58,9 @@ class VrShell : public device::GvrDelegate, content::WebContentsObserver {
  public:
   VrShell(JNIEnv* env, jobject obj,
           content::WebContents* main_contents,
-          ui::WindowAndroid* content_window,
+          ui::ViewRoot* content_view_root,
           content::WebContents* ui_contents,
-          ui::WindowAndroid* ui_window,
+          ui::ViewRoot* ui_view_root,
           bool for_web_vr,
           VrShellDelegate* delegate,
           gvr_context* gvr_api,