Swap to foreground tab when following links that open in a new tab/window in VR Shell.

chrome/browser/android/vr_shell/vr_web_contents_observer.cc

Index: chrome/browser/android/vr_shell/vr_web_contents_observer.cc
diff --git a/chrome/browser/android/vr_shell/vr_web_contents_observer.cc b/chrome/browser/android/vr_shell/vr_web_contents_observer.cc
index 77979416279f680ef4e09c10bc666036811b4c32..7d819eedd497cec49cf3ea25bcdb748c9b39d276 100644
--- a/chrome/browser/android/vr_shell/vr_web_contents_observer.cc
+++ b/chrome/browser/android/vr_shell/vr_web_contents_observer.cc
@@ -81,6 +81,11 @@ void VrWebContentsObserver::WasHidden() {
   vr_shell_->ContentWasHidden();
 }
 
+void VrWebContentsObserver::WasShown() {
+  vr_shell_->ContentWasShown();
+}
+
+
 void VrWebContentsObserver::MainFrameWasResized(bool width_changed) {
   vr_shell_->ContentFrameWasResized(width_changed);
 }