PROTOTYPE (incomplete): Add quad renderer and stub bits to handle security warnings.

chrome/browser/android/vr_shell/vr_gl_thread.cc

Index: chrome/browser/android/vr_shell/vr_gl_thread.cc
diff --git a/chrome/browser/android/vr_shell/vr_gl_thread.cc b/chrome/browser/android/vr_shell/vr_gl_thread.cc
index 0697b1d71fa8e3f0bd46a8af500185b2f53c68c3..8b341c94d98cd49938ba3f82e85447c423d98c80 100644
--- a/chrome/browser/android/vr_shell/vr_gl_thread.cc
+++ b/chrome/browser/android/vr_shell/vr_gl_thread.cc
@@ -34,6 +34,14 @@ VrGLThread::~VrGLThread() {
 void VrGLThread::Init() {
   scene_ = base::MakeUnique<UiScene>();
   scene_manager_ = base::MakeUnique<UiSceneManager>(scene_.get());
+
+  // TODO: Clear up the init order.  We should create the GL object first, as it

[cjgrant, 2017/04/19 16:24:52]

Elaborating:  This isn't a big deal, but we should do it correctly so that we
don't get sporadic failures on exit.

+  // is the tool used to draw the scene, and it supplies texture IDs as elements
+  // are created.  However, the GL object also needs a pointer to the scene, so
+  // it has something to draw.  Possibly just supply the scene pointer to
+  // VrShellGl after it's created.  Whatever happens, be sure to tear things
+  // down later in the inverse order.
+
   vr_shell_gl_ = base::MakeUnique<VrShellGl>(
       std::move(weak_vr_shell_), std::move(main_thread_task_runner_), gvr_api_,
       initially_web_vr_, reprojected_rendering_, scene_.get());