Make ViewRoot the top of the ViewAndroid tree

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 81c0ed93a506f108f34cc22ca34ea0ce49e6fb75..5b8b419cbe841c4a5194a661ac3ccbd398d07cee 100644
--- a/chrome/browser/android/vr_shell/vr_shell.h
+++ b/chrome/browser/android/vr_shell/vr_shell.h
@@ -33,7 +33,7 @@ class WebContents;
 }
 
 namespace ui {
-class WindowAndroid;
+class ViewRoot;
 }
 
 namespace vr_shell {
@@ -64,11 +64,12 @@ class VrMetricsHelper;
 // must only be used on the UI thread.
 class VrShell : public device::GvrDelegate, content::WebContentsObserver {
  public:
-  VrShell(JNIEnv* env, jobject obj,
+  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,