Exit VR Shell on pause (And fix a bunch of minor bugs).

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 af69ba1a03620671880aa90cf4f915f72e35e64e..d4ce924bb39e442872567825273be37bf2807438 100644
--- a/chrome/browser/android/vr_shell/vr_shell_delegate.cc
+++ b/chrome/browser/android/vr_shell/vr_shell_delegate.cc
@@ -55,12 +55,11 @@ VrShellDelegate* VrShellDelegate::getNativeDelegate(
   return reinterpret_cast<VrShellDelegate*>(native_delegate);
 }
 
-bool VrShellDelegate::ExitWebVRIfNecessary(JNIEnv* env, jobject obj) {
+void VrShellDelegate::ExitWebVRIfNecessary(JNIEnv* env, jobject obj) {
   if (!device_provider_)
-    return false;
+    return;
 
   device_provider_->OnGvrDelegateRemoved();
-  return true;
 }
 
 bool VrShellDelegate::RequestWebVRPresent(