Call xglMakeCurrent for each command buffer to allow for multiple GL contexts...

gpu/command_buffer/service/x_utils.cc

 // Copyright (c) 2009 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.
 
 // This class implements the XWindowWrapper class.
 
 #include <dlfcn.h>
 
 #include "gpu/command_buffer/service/precompile.h"
 #include "gpu/command_buffer/common/logging.h"
@@ skipping 56 matching lines @@
 
   if (!glewIsSupported("GL_VERSION_2_0")) {
     LOG(ERROR) << "GL implementation doesn't support GL version 2.0";
     return false;
   }
 
   return true;
 }
 
 bool XWindowWrapper::MakeCurrent() {
+  if (glXGetCurrentDrawable() == window &&
+      glXGetCurrentContext() == context_) {
+    return true;
+  }
   if (glXMakeCurrent(display_, window_, context_) != True) {
     glXDestroyContext(display_, context_);
     context_ = 0;
     DLOG(ERROR) << "Couldn't make context current.";
     return false;
   }
   return true;
 }
 
 void XWindowWrapper::Destroy() {
   Bool result = glXMakeCurrent(display_, 0, 0);
   // glXMakeCurrent isn't supposed to fail when unsetting the context, unless
   // we have pending draws on an invalid window - which shouldn't be the case
   // here.
   DCHECK(result);
   if (context_) {
     glXDestroyContext(display_, context_);
     context_ = 0;
   }
 }
 
 void XWindowWrapper::SwapBuffers() {
   glXSwapBuffers(display_, window_);
 }
 
 }  // namespace gpu