[Ozone-Demo] Add support for NativeDisplayDelegate

ui/ozone/demo/gl_renderer.cc

Index: ui/ozone/demo/gl_renderer.cc
diff --git a/ui/ozone/demo/gl_renderer.cc b/ui/ozone/demo/gl_renderer.cc
index f8141494f579bd49f6c99b0018ad3b2cdb32b0ec..8e0fcfe59ee206c0fdc27338bc2813496b550799 100644
--- a/ui/ozone/demo/gl_renderer.cc
+++ b/ui/ozone/demo/gl_renderer.cc
@@ -44,6 +44,8 @@ bool GlRenderer::Initialize() {
 void GlRenderer::RenderFrame() {
   float fraction = NextFraction();
 
+  context_->MakeCurrent(surface_.get());

[alexst (slow to review), 2015/02/11 15:36:05]

Why do we need this on every render frame?

[dnicoara, 2015/02/11 16:46:37]

If we have multiple renderers, each will have its own context and surface. This
needs to make sure it is rendering in the correct surface.

+
   glViewport(0, 0, size_.width(), size_.height());
   glClearColor(1 - fraction, fraction, 0.0, 1.0);
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);