Fix double-deletion of VR Shell when exiting webVR in onPause.

chrome/browser/android/vr_shell/vr_shell_delegate.cc

Index: chrome/browser/android/vr_shell/vr_shell_delegate.cc
diff --git a/chrome/browser/android/vr_shell/vr_shell_delegate.cc b/chrome/browser/android/vr_shell/vr_shell_delegate.cc
index 5099fec8f32be95c04c5d8c96c28ad85a398f070..cd01c36309d3b1f1be210be0c199200019a69616 100644
--- a/chrome/browser/android/vr_shell/vr_shell_delegate.cc
+++ b/chrome/browser/android/vr_shell/vr_shell_delegate.cc
@@ -63,13 +63,6 @@ base::WeakPtr<device::GvrDeviceProvider> VrShellDelegate::GetDeviceProvider() {
   return device_provider_;
 }
 
-void VrShellDelegate::ExitWebVRIfNecessary(JNIEnv* env, jobject obj) {
-  if (!device_provider_)
-    return;
-
-  device_provider_->OnGvrDelegateRemoved();
-}
-
 bool VrShellDelegate::RequestWebVRPresent(
     base::WeakPtr<device::GvrDeviceProvider> device_provider) {
   // Only set one device provider at a time