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

ui/gl/gl_context_stub.cc

Index: ui/gl/gl_context_stub.cc
diff --git a/ui/gl/gl_context_stub.cc b/ui/gl/gl_context_stub.cc
index 2b72c8f8c677d6095bb4b0b5db92434f77aa9dc2..7c63ff2e46c6e1c1b0ca94f939c1ff99a0905c1d 100644
--- a/ui/gl/gl_context_stub.cc
+++ b/ui/gl/gl_context_stub.cc
@@ -6,7 +6,7 @@
 
 namespace gfx {
 
-GLContextStub::GLContextStub() : GLContext(NULL) {}
+GLContextStub::GLContextStub() : GLContextReal(NULL) {}
 
 bool GLContextStub::Initialize(
     GLSurface* compatible_surface, GpuPreference gpu_preference) {
@@ -16,12 +16,13 @@ bool GLContextStub::Initialize(
 void GLContextStub::Destroy() {}
 
 bool GLContextStub::MakeCurrent(GLSurface* surface) {
-  SetCurrent(this, surface);
+  SetCurrent(surface);
   SetRealGLApi();
   return true;
 }
 
 void GLContextStub::ReleaseCurrent(GLSurface* surface) {
+  SetCurrent(NULL);
 }
 
 bool GLContextStub::IsCurrent(GLSurface* surface) {