Replace SmartPointer<T> with unique_ptr<T>

src/mips64/codegen-mips64.cc

Index: src/mips64/codegen-mips64.cc
diff --git a/src/mips64/codegen-mips64.cc b/src/mips64/codegen-mips64.cc
index ae4e37ef283202156e0d7a52a5b61d95402bead3..943c2a6e639a0314667411be3365563f36fb6d37 100644
--- a/src/mips64/codegen-mips64.cc
+++ b/src/mips64/codegen-mips64.cc
@@ -6,6 +6,8 @@
 
 #if V8_TARGET_ARCH_MIPS64
 
+#include <memory>
+
 #include "src/codegen.h"
 #include "src/macro-assembler.h"
 #include "src/mips64/simulator-mips64.h"
@@ -1050,7 +1052,7 @@ 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));