Implement WebVR presentation pausing for VR Shell Menu Mode

chrome/browser/android/vr_shell/vr_shell_delegate.h

Index: chrome/browser/android/vr_shell/vr_shell_delegate.h
diff --git a/chrome/browser/android/vr_shell/vr_shell_delegate.h b/chrome/browser/android/vr_shell/vr_shell_delegate.h
index 4ac1dfc859823f20b92b8a290677039ea304caf2..6946ddcf000e2c8b70f2a4138e51665b374fe209 100644
--- a/chrome/browser/android/vr_shell/vr_shell_delegate.h
+++ b/chrome/browser/android/vr_shell/vr_shell_delegate.h
@@ -11,6 +11,10 @@
 #include "base/macros.h"
 #include "device/vr/android/gvr/gvr_delegate.h"
 
+namespace device {
+class GvrDeviceProvider;
+}
+
 namespace vr_shell {
 
 class VrShell;
@@ -22,6 +26,8 @@ class VrShellDelegate : public device::GvrDelegateProvider {
 
   static VrShellDelegate* getNativeDelegate(JNIEnv* env, jobject jdelegate);
 
+  device::GvrDeviceProvider* GetDeviceProvider() { return device_provider_; }
+
   // Called by the Java VrShellDelegate. Returns true if the GvrDeviceProvider
   // needs to handle shutdown first.
   void ExitWebVRIfNecessary(JNIEnv* env, jobject obj);