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

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 6de2fc3f3b2cac1f3551eff01f4300d00a2d07ef..52dc521a3af889e5271a714b3a8ea4663a926297 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -3711,7 +3711,7 @@ void FullCodeGenerator::EmitValueOf(CallRuntime* expr) {
 void FullCodeGenerator::EmitDateField(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 2);
-  DCHECK_NE(NULL, args->at(1)->AsLiteral());
+  DCHECK(args->at(1)->AsLiteral());
   Smi* index = Smi::cast(*(args->at(1)->AsLiteral()->value()));
 
   VisitForAccumulatorValue(args->at(0));  // Load the object.
@@ -4063,7 +4063,7 @@ void FullCodeGenerator::EmitGetFromCache(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK_EQ(2, args->length());
 
-  DCHECK_NE(NULL, args->at(0)->AsLiteral());
+  DCHECK(args->at(0)->AsLiteral());
   int cache_id = Smi::cast(*(args->at(0)->AsLiteral()->value()))->value();
 
   Handle<FixedArray> jsfunction_result_caches(