Added hello-triangle demo....

gpu/demos/hello_triangle/main.cc

+// Copyright (c) 2009 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.
+
+// This is a simple example that draws a single triangle with
+// a minimal vertex/fragment shader.  The purpose of this
+// example is to demonstrate the basic concepts of
+// OpenGL ES 2.0 rendering.
+
+#include "gpu/demos/app_framework/application.h"
+#include "third_party/gles_book_examples/Chapter_2/Hello_Triangle/Hello_Triangle.h"
+
+namespace gpu_demos {
+class HelloTriangle : public Application {
+ public:
+  HelloTriangle();
+  ~HelloTriangle();
+
+  bool Init();
+
+ protected:
+  virtual void Draw();
+
+ private:
+  ESContext context_;
+  HTUserData user_data_;
+
+  DISALLOW_COPY_AND_ASSIGN(HelloTriangle);
+};
+
+HelloTriangle::HelloTriangle() {
+  esInitContext(&context_);
+
+  memset(&user_data_, 0, sizeof(HTUserData));
+  context_.userData = &user_data_;
+}
+
+HelloTriangle::~HelloTriangle() {
+  htShutDown(&context_);
+}
+
+bool HelloTriangle::Init() {
+  if (!Application::InitRenderContext()) return false;
+
+  context_.width = width();
+  context_.height = height();
+  if (!htInit(&context_)) return false;
+
+  return true;
+}
+
+void HelloTriangle::Draw() {
+  htDraw(&context_);
+}
+}  // namespace gpu_demos
+
+int main(int argc, char *argv[]) {
+  gpu_demos::HelloTriangle app;
+  if (!app.Init()) {
+    printf("Could not init.\n");
+    return EXIT_FAILURE;
+  }
+
+  app.MainLoop();
+  return EXIT_SUCCESS;
+}