Ensure SurfaceManager is only ever used from one thread.

cc/surfaces/surface_manager.cc

Index: cc/surfaces/surface_manager.cc
diff --git a/cc/surfaces/surface_manager.cc b/cc/surfaces/surface_manager.cc
index 363f0924439f54ca259ab10ccafd99defc8abeec..1e3699d30a5c82afe399c92c5288247ff56f943c 100644
--- a/cc/surfaces/surface_manager.cc
+++ b/cc/surfaces/surface_manager.cc
@@ -10,24 +10,29 @@
 namespace cc {
 
 SurfaceManager::SurfaceManager() {
+  thread_checker_.DetachFromThread();
 }
 
 SurfaceManager::~SurfaceManager() {
+  DCHECK(thread_checker_.CalledOnValidThread());
 }
 
 void SurfaceManager::RegisterSurface(Surface* surface) {
+  DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(surface);
   DCHECK(!surface_map_.count(surface->surface_id()));
   surface_map_[surface->surface_id()] = surface;
 }
 
 void SurfaceManager::DeregisterSurface(SurfaceId surface_id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
   SurfaceMap::iterator it = surface_map_.find(surface_id);
   DCHECK(it != surface_map_.end());
   surface_map_.erase(it);
 }
 
 Surface* SurfaceManager::GetSurfaceForId(SurfaceId surface_id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
   SurfaceMap::iterator it = surface_map_.find(surface_id);
   if (it == surface_map_.end())
     return NULL;
@@ -35,6 +40,7 @@ Surface* SurfaceManager::GetSurfaceForId(SurfaceId surface_id) {
 }
 
 void SurfaceManager::SurfaceModified(SurfaceId surface_id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
   FOR_EACH_OBSERVER(
       SurfaceDamageObserver, observer_list_, OnSurfaceDamaged(surface_id));
 }