ozone: fix crash when running video decode unittests.

ui/gl/gl_surface_ozone.cc

Index: ui/gl/gl_surface_ozone.cc
diff --git a/ui/gl/gl_surface_ozone.cc b/ui/gl/gl_surface_ozone.cc
index da80397654374248b9305f0701a7c0ba0de7eaa5..3fe9b03f52dbacf0fc13f657c6a125e222e4021c 100644
--- a/ui/gl/gl_surface_ozone.cc
+++ b/ui/gl/gl_surface_ozone.cc
@@ -603,9 +603,11 @@ void GLSurfaceOzoneSurfacelessSurfaceImpl::Destroy() {
   }
 
   if (!was_current) {
-    previous_context->MakeCurrent(previous_surface.get());
-  } else {
-    context_->ReleaseCurrent(this);
+    if (previous_context) {

[spang, 2016/04/13 14:00:49]

Seems like it should be

if (!was_current && previous_context) {
  previous_context->MakeCurrent(previous_surface.get());
} else {
  context_->ReleaseCurrent(this);
}

[spang, 2016/04/13 14:16:20]

I guess it's fine the way it is, if you fall through here with the surface left
current it'll clear it it in GLSurface::~GLSurface.

+      previous_context->MakeCurrent(previous_surface.get());
+    } else {
+      context_->ReleaseCurrent(this);
+    }
   }
 }