opengl renderer: create rendering subwindow

The application provides the window handle to which the
OpenglRenderer should render to however only a sub-region of
this window needs to be rendered. This change adds this functionality
by creating a native child subwindow into which rendering will happen.

tools/emulator/opengl/host/libs/libOpenglRender/NativeSubWindow.h

@@ -0,0 +1,29 @@
+/*
+* Copyright (C) 2011 The Android Open Source Project
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+#ifndef NATIVE_SUB_WINDOW_H
+#define NATIVE_SUB_WINDOW_H
+
+#include <EGL/egl.h>
+#include "libOpenglRender/render_api.h"
+
+EGLNativeWindowType createSubWindow(FBNativeWindowType p_window,
+                                    EGLNativeDisplayType* display_out,
+                                    int x, int y,int width, int height);
+
+
+void destroySubWindow(EGLNativeDisplayType dis,EGLNativeWindowType win);
+
+#endif