Convert //extensions/{common,shell} from scoped_ptr to std::unique_ptr

extensions/common/permissions/api_permission.cc

Index: extensions/common/permissions/api_permission.cc
diff --git a/extensions/common/permissions/api_permission.cc b/extensions/common/permissions/api_permission.cc
index 77a13172cdcbe0d274bc6f94506495bb7d4d99b4..db84d8ae0f04f572418b81ca1c5b64b7c6b63bd5 100644
--- a/extensions/common/permissions/api_permission.cc
+++ b/extensions/common/permissions/api_permission.cc
@@ -46,8 +46,8 @@ class SimpleAPIPermission : public APIPermission {
     return (value == NULL);
   }
 
-  scoped_ptr<base::Value> ToValue() const override {
-    return scoped_ptr<base::Value>();
+  std::unique_ptr<base::Value> ToValue() const override {
+    return std::unique_ptr<base::Value>();
   }
 
   APIPermission* Clone() const override {