Fix destruction order between SurfaceManger and OffscreenCanvasSurfaceImpl

content/browser/compositor/surface_utils.cc

Index: content/browser/compositor/surface_utils.cc
diff --git a/content/browser/compositor/surface_utils.cc b/content/browser/compositor/surface_utils.cc
index 9f79cb74b55a776b0de5a845d1932e3f4659a6f7..09739c5ca4c892b05ce0715edc55a361025e37df 100644
--- a/content/browser/compositor/surface_utils.cc
+++ b/content/browser/compositor/surface_utils.cc
@@ -172,6 +172,8 @@ cc::SurfaceManager* GetSurfaceManager() {
   return CompositorImpl::GetSurfaceManager();
 #else
   ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
+  if (factory == NULL)
+      return nullptr;
   return factory->GetSurfaceManager();
 #endif
 }