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

src/ppc/full-codegen-ppc.cc

Index: src/ppc/full-codegen-ppc.cc
diff --git a/src/ppc/full-codegen-ppc.cc b/src/ppc/full-codegen-ppc.cc
index b9870bbcc5a28866b00f9261de222ac73a265b02..af29bcdbbbbbbe6379c91dcdc3d9a13ef089709a 100644
--- a/src/ppc/full-codegen-ppc.cc
+++ b/src/ppc/full-codegen-ppc.cc
@@ -3755,7 +3755,7 @@ 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.
@@ -4091,7 +4091,7 @@ void FullCodeGenerator::EmitRegExpConstructResult(CallRuntime* expr) {
 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(