ozone: fix crash when running video decode unittests.

ui/gl/gl_surface_ozone.cc

 // Copyright 2014 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.
 
 #include "ui/gl/gl_surface.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 585 matching lines @@
       texture = 0;
     glDeleteFramebuffersEXT(1, &fbo_);
     fbo_ = 0;
   }
   for (auto image : images_) {
     if (image)
       image->Destroy(true);
   }
 
   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);
+    }
   }
 }
 
 bool GLSurfaceOzoneSurfacelessSurfaceImpl::IsSurfaceless() const {
   return false;
 }
 
 GLSurfaceOzoneSurfacelessSurfaceImpl::~GLSurfaceOzoneSurfacelessSurfaceImpl() {
   Destroy();
 }
@@ skipping 161 matching lines @@
   }
 }
 
 EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay() {
   return ui::OzonePlatform::GetInstance()
       ->GetSurfaceFactoryOzone()
       ->GetNativeDisplay();
 }
 
 }  // namespace gfx