Enable magic window mode with new Gvr

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/NonPresentingGvrContext.java

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.vr_shell;
+
+import android.app.Activity;
+import android.os.StrictMode;
+
+import com.google.vr.ndk.base.GvrLayout;
+
+import org.chromium.base.Log;
+import org.chromium.base.annotations.UsedByReflection;
+
+/**
+ * Creates an active GvrContext from a detached GvrLayout. This is used by magic window mode.
+ */
+@UsedByReflection("VrShellDelegate.java")
+public class NonPresentingGvrContext implements NonPresentingGvrContextInterface {
+    private static final String TAG = "NPGvrContext";
+    private GvrLayout mGvrLayout;
+
+    @UsedByReflection("VrShellDelegate.java")
+    public NonPresentingGvrContext(Activity activity) {
+        mGvrLayout = new GvrLayout(activity);
+    }
+
+    @Override
+    public long getNativeGvrContext() {
+        long nativeGvrContext = 0;
+        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
+        try {
+            nativeGvrContext = mGvrLayout.getGvrApi().getNativeGvrContext();
+        } catch (Exception ex) {
+            Log.e(TAG, "Unable to instantiate GvrApi", ex);
+            return 0;
+        } finally {
+            StrictMode.setThreadPolicy(oldPolicy);
+        }
+        return nativeGvrContext;
+    }
+
+    @Override
+    public void resume() {
+        mGvrLayout.onResume();
+    }
+
+    @Override
+    public void pause() {
+        mGvrLayout.onPause();
+    }
+
+    @Override
+    public void shutdown() {
+        mGvrLayout.shutdown();
+    }
+}