Introduce ChromeVR to Chrome on Android (behind a build flag)

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

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/TextureHelper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/TextureHelper.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/TextureHelper.java
new file mode 100644
index 0000000000000000000000000000000000000000..63bcf4c3806ce61325e355ee1510e182199c2b87
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/TextureHelper.java
@@ -0,0 +1,36 @@
+// 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 static android.opengl.GLES20.GL_NEAREST;
+import static android.opengl.GLES20.GL_TEXTURE_MAG_FILTER;
+import static android.opengl.GLES20.GL_TEXTURE_MIN_FILTER;
+import static android.opengl.GLES20.glBindTexture;
+import static android.opengl.GLES20.glGenTextures;
+import static android.opengl.GLES20.glTexParameteri;
+
+import android.opengl.GLES11Ext;
+
+/**
+ * Helper class for working with OpenGL textures.
+ */
+public class TextureHelper {
+    /**
+     * Create a new GLES11Ext.GL_TEXTURE_EXTERNAL_OES texture handle.
+     * @return New texture handle.
+     */
+    public static int createExternalTextureHandle() {
+        int[] textureDataHandle = new int[1];
+        glGenTextures(1, textureDataHandle, 0);
+        if (textureDataHandle[0] != 0) {
+            glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, textureDataHandle[0]);
+            glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+            glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+            return textureDataHandle[0];
+        } else {
+            throw new RuntimeException("Error generating texture handle.");
+        }
+    }
+}