content: Add ContextProviderFactory to create a render ContextProvider.

content/browser/gpu/gpu_surface_tracker.cc

Index: content/browser/gpu/gpu_surface_tracker.cc
diff --git a/content/browser/gpu/gpu_surface_tracker.cc b/content/browser/gpu/gpu_surface_tracker.cc
index d04a0e2f4249d3279da4601389e84bd64efbe768..3c6754c4ba991542a6e8e27b6e57ff09903db2a8 100644
--- a/content/browser/gpu/gpu_surface_tracker.cc
+++ b/content/browser/gpu/gpu_surface_tracker.cc
@@ -36,6 +36,11 @@ int GpuSurfaceTracker::AddSurfaceForNativeWidget(
   return surface_handle;
 }
 
+bool GpuSurfaceTracker::IsValidSurfaceHandle(
+    gpu::SurfaceHandle surface_handle) const {
+  return surface_map_.find(surface_handle) != surface_map_.end();
+}
+
 void GpuSurfaceTracker::RemoveSurface(gpu::SurfaceHandle surface_handle) {
   base::AutoLock lock(lock_);
   DCHECK(surface_map_.find(surface_handle) != surface_map_.end());