App button click exits WebVR presentation.

chrome/browser/android/vr_shell/vr_shell.cc

Index: chrome/browser/android/vr_shell/vr_shell.cc
diff --git a/chrome/browser/android/vr_shell/vr_shell.cc b/chrome/browser/android/vr_shell/vr_shell.cc
index 49362ef2b89d248065e793b4d0f8bb1241d38b27..d1ba444798fbc23013e5e8128ccf9541fc23b08b 100644
--- a/chrome/browser/android/vr_shell/vr_shell.cc
+++ b/chrome/browser/android/vr_shell/vr_shell.cc
@@ -431,9 +431,6 @@ void VrShell::DoUiAction(const UiAction action,
       }
       // Otherwise handle in java.
       break;
-    case EXIT_PRESENT:
-      delegate_provider_->ExitWebVRPresent();
-      return;
     default:
       break;
   }
@@ -496,6 +493,10 @@ void VrShell::ForceExitVr() {
   Java_VrShellImpl_forceExitVr(env, j_vr_shell_.obj());
 }
 
+void VrShell::ExitPresent() {
+  delegate_provider_->ExitWebVRPresent();
+}
+
 void VrShell::OnVRVsyncProviderRequest(
     device::mojom::VRVSyncProviderRequest request) {
   PostToGlThreadWhenReady(base::Bind(&VrShellGl::OnRequest,