Initial switch to Chromium-style CHECK_* and DCHECK_* macros.

src/compiler/gap-resolver.cc

Index: src/compiler/gap-resolver.cc
diff --git a/src/compiler/gap-resolver.cc b/src/compiler/gap-resolver.cc
index f369607170b2429c9c0d21f19f6836770b53dc59..4089024685ebc2ae28dc786786bd06e207074c99 100644
--- a/src/compiler/gap-resolver.cc
+++ b/src/compiler/gap-resolver.cc
@@ -65,7 +65,7 @@ void GapResolver::PerformMove(ZoneList<MoveOperands>* moves,
 
   // Clear this move's destination to indicate a pending move.  The actual
   // destination is saved on the side.
-  DCHECK_NOT_NULL(move->source());  // Or else it will look eliminated.
+  DCHECK(move->source());  // Or else it will look eliminated.
   InstructionOperand* destination = move->destination();
   move->set_destination(NULL);