Ignore GL calls when the context is lost.

src/libGLESv2/main.cpp

@@ -94,6 +94,16 @@ Context *getContext()
     return current->context;
 }
 
+Context *getNonLostContext()
+{
+    Context *context = getContext();
+    
+    if (context && !context->isContextLost())
+        return context;
+
+    return NULL;
+}
+
 egl::Display *getDisplay()
 {
     Current *current = (Current*)TlsGetValue(currentTLS);

src/libGLESv2/main.h

@@ -29,6 +29,7 @@ struct Current
 void makeCurrent(Context *context, egl::Display *display, egl::Surface *surface);
 
 Context *getContext();
+Context *getNonLostContext();
 egl::Display *getDisplay();
 
 IDirect3DDevice9 *getDevice();