GPU: Keep track of the last real context and real surface made current.

ui/gl/gl_context_wgl.cc

Index: ui/gl/gl_context_wgl.cc
diff --git a/ui/gl/gl_context_wgl.cc b/ui/gl/gl_context_wgl.cc
index 916e49df5fcdcf9d1d66275686775d4135e6cc03..ccb457b27b04e588899638ca4c371348ccf2eb5c 100644
--- a/ui/gl/gl_context_wgl.cc
+++ b/ui/gl/gl_context_wgl.cc
@@ -111,7 +111,7 @@ bool GLContextWGL::IsCurrent(GLSurface* surface) {
   // If our context is current then our notion of which GLContext is
   // current must be correct. On the other hand, third-party code
   // using OpenGL might change the current context.
-  DCHECK(!native_context_is_current || (GetCurrent() == this));
+  DCHECK(!native_context_is_current || (GetRealCurrent() == this));
 
   if (!native_context_is_current)
     return false;