Remove offscreen compositor contexts.

cc/test/fake_layer_tree_host_client.cc

Index: cc/test/fake_layer_tree_host_client.cc
diff --git a/cc/test/fake_layer_tree_host_client.cc b/cc/test/fake_layer_tree_host_client.cc
index 1ee0bb80c17cd4835e87ad2b7dd15af17886c642..975f6878cc5dff1ffa499b4271aec19359222f78 100644
--- a/cc/test/fake_layer_tree_host_client.cc
+++ b/cc/test/fake_layer_tree_host_client.cc
@@ -35,12 +35,4 @@ scoped_ptr<OutputSurface> FakeLayerTreeHostClient::CreateOutputSurface(
   return FakeOutputSurface::Create3d().PassAs<OutputSurface>();
 }
 
-scoped_refptr<ContextProvider>
-FakeLayerTreeHostClient::OffscreenContextProvider() {
-  if (!offscreen_contexts_.get() ||
-      offscreen_contexts_->DestroyedOnMainThread())
-    offscreen_contexts_ = TestContextProvider::Create();
-  return offscreen_contexts_;
-}
-
 }  // namespace cc