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

ui/gl/gl_gl_api_implementation.cc

Index: ui/gl/gl_gl_api_implementation.cc
diff --git a/ui/gl/gl_gl_api_implementation.cc b/ui/gl/gl_gl_api_implementation.cc
index 1002dbd278842f0e51a8868f58b1bea16bf5f5fe..44ae6c6f3df14aa8be95e3d5ff0372f5e2f1b299 100644
--- a/ui/gl/gl_gl_api_implementation.cc
+++ b/ui/gl/gl_gl_api_implementation.cc
@@ -268,8 +268,9 @@ bool VirtualGLApi::MakeCurrent(GLContext* virtual_context, GLSurface* surface) {
     }
   }
 
-  DCHECK(GLSurface::GetCurrent());
-  DCHECK(real_context_->IsCurrent(GLSurface::GetCurrent()));
+  DCHECK_EQ(real_context_, GLContext::GetRealCurrent());
+  DCHECK(GLSurface::GetRealCurrent());
+  DCHECK(real_context_->IsCurrent(GLSurface::GetRealCurrent()));

[jonathan.backer, 2013/05/23 21:00:53]

Switching to a real surface is necessary because GLContextVirtual::IsCurrent is
permissive (as an optimization).

   DCHECK(virtual_context->IsCurrent(surface));
 
   if (switched_contexts || virtual_context != current_context_) {
@@ -289,6 +290,7 @@ bool VirtualGLApi::MakeCurrent(GLContext* virtual_context, GLSurface* surface) {
     SetGLApi(temp);
   }
   SetGLApi(this);
+
   return true;
 }