gpu: Bind dummy GL API when no context is current

ui/gl/gl_context_glx.cc

 // Copyright (c) 2012 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.
 
 extern "C" {
 #include <X11/Xlib.h>
 }
 
 #include "ui/gl/gl_context_glx.h"
 
@@ skipping 80 matching lines @@
                       static_cast<GLXContext>(context_));
     context_ = NULL;
   }
 }
 
 bool GLContextGLX::MakeCurrent(GLSurface* surface) {
   DCHECK(context_);
   if (IsCurrent(surface))
     return true;
 
+  ScopedReleaseCurrent release_current;
   TRACE_EVENT0("gpu", "GLContextGLX::MakeCurrent");
   if (!glXMakeContextCurrent(
       display_,
       reinterpret_cast<GLXDrawable>(surface->GetHandle()),
       reinterpret_cast<GLXDrawable>(surface->GetHandle()),
       static_cast<GLXContext>(context_))) {
     LOG(ERROR) << "Couldn't make context current with X drawable.";
     Destroy();
     return false;
   }
 
   // Set this as soon as the context is current, since we might call into GL.
   SetRealGLApi();
 
   SetCurrent(surface);
   if (!InitializeDynamicBindings()) {
-    ReleaseCurrent(surface);
     Destroy();
     return false;
   }
 
   if (!surface->OnMakeCurrent(this)) {
     LOG(ERROR) << "Could not make current.";
-    ReleaseCurrent(surface);
     Destroy();
     return false;
   }
 
+  release_current.Cancel();
   return true;
 }
 
 void GLContextGLX::ReleaseCurrent(GLSurface* surface) {
   if (!IsCurrent(surface))
     return;
 
   SetCurrent(NULL);
   if (!glXMakeContextCurrent(display_, 0, 0, 0))
     LOG(ERROR) << "glXMakeCurrent failed in ReleaseCurrent";
@@ skipping 68 matching lines @@
 
 bool GLContextGLX::WasAllocatedUsingRobustnessExtension() {
   return GLSurfaceGLX::IsCreateContextRobustnessSupported();
 }
 
 GLContextGLX::~GLContextGLX() {
   Destroy();
 }
 
 }  // namespace gfx