Replace SmartPointer<T> with unique_ptr<T>

src/mips/codegen-mips.cc

Index: src/mips/codegen-mips.cc
diff --git a/src/mips/codegen-mips.cc b/src/mips/codegen-mips.cc
index ae1ff96e54565b75d71c9e3a6e0cf9f5bd01b571..8aaeaca367860d623132e57def80f6dee80a1b46 100644
--- a/src/mips/codegen-mips.cc
+++ b/src/mips/codegen-mips.cc
@@ -6,6 +6,8 @@
 
 #if V8_TARGET_ARCH_MIPS
 
+#include <memory>
+
 #include "src/codegen.h"
 #include "src/macro-assembler.h"
 #include "src/mips/simulator-mips.h"
@@ -1051,7 +1053,7 @@ CodeAgingHelper::CodeAgingHelper(Isolate* isolate) {
   // to avoid overloading the stack in stress conditions.
   // DONT_FLUSH is used because the CodeAgingHelper is initialized early in
   // the process, before MIPS simulator ICache is setup.
-  base::SmartPointer<CodePatcher> patcher(
+  std::unique_ptr<CodePatcher> patcher(
       new CodePatcher(isolate, young_sequence_.start(),
                       young_sequence_.length() / Assembler::kInstrSize,
                       CodePatcher::DONT_FLUSH));