Small documentation and stylistic changes.

Test: art/test.py
Change-Id: Ibc74ee4783314266bf1d027811715058626c57c8
diff --git a/runtime/signal_catcher.cc b/runtime/signal_catcher.cc
index d9c4da9..9c3afbb 100644
--- a/runtime/signal_catcher.cc
+++ b/runtime/signal_catcher.cc
@@ -207,7 +207,7 @@
 
 void SignalCatcher::HandleSigUsr1() {
   LOG(INFO) << "SIGUSR1 forcing GC (no HPROF) and profile save";
-  Runtime::Current()->GetHeap()->CollectGarbage(false);
+  Runtime::Current()->GetHeap()->CollectGarbage(/* clear_soft_references */ false);
   ProfileSaver::ForceProcessProfiles();
 }