content/blimp: Set up hooks for enabling LTHRemote in the renderer.

cc/blimp/layer_tree_host_remote.cc

Index: cc/blimp/layer_tree_host_remote.cc
diff --git a/cc/blimp/layer_tree_host_remote.cc b/cc/blimp/layer_tree_host_remote.cc
index df457b79f99dc27c4ca39271efa4a06c7ebc65c3..56418c88418a2725a4e77caa8a73e0f68c70bffc 100644
--- a/cc/blimp/layer_tree_host_remote.cc
+++ b/cc/blimp/layer_tree_host_remote.cc
@@ -235,8 +235,9 @@ void LayerTreeHostRemote::DidStopFlinging() {
 
 void LayerTreeHostRemote::SetDebugState(
     const LayerTreeDebugState& debug_state) {
-  // TODO(khushalsagar): Figure out if we need to send these to the client.
-  NOTREACHED();
+  // If any debugging needs to be enabled, ideally it should be using the
+  // compositor on the client directly. But the setup code will always set this
+  // on initialization, even if the settings end up being a no-op.
 }
 
 const LayerTreeDebugState& LayerTreeHostRemote::GetDebugState() const {