Make blink::JSONValue (and subclasses) use unique_ptr rather than RefPtrs.

third_party/WebKit/Source/platform/JSONValues.h

Index: third_party/WebKit/Source/platform/JSONValues.h
diff --git a/third_party/WebKit/Source/platform/JSONValues.h b/third_party/WebKit/Source/platform/JSONValues.h
index 1789d4225525204b56fd66741fa42c3930c09947..1425c46aeaf5861bd4acd29cbd581c66d72c0525 100644
--- a/third_party/WebKit/Source/platform/JSONValues.h
+++ b/third_party/WebKit/Source/platform/JSONValues.h
@@ -35,12 +35,14 @@
 #include "wtf/Allocator.h"
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
-#include "wtf/RefCounted.h"
+#include "wtf/Noncopyable.h"
 #include "wtf/TypeTraits.h"
 #include "wtf/Vector.h"
 #include "wtf/text/StringHash.h"
 #include "wtf/text/WTFString.h"
 
+#include <memory>
+
 namespace blink {
 
 class JSONValue;
@@ -52,15 +54,16 @@ namespace blink {
 class JSONArray;
 class JSONObject;
 
-class PLATFORM_EXPORT JSONValue : public RefCounted<JSONValue> {
+class PLATFORM_EXPORT JSONValue {
+    WTF_MAKE_NONCOPYABLE(JSONValue);

[jbroman, 2016/08/04 15:17:30]

You may also want USING_FAST_MALLOC(JSONValue), as RefCounted<T> are allocated
with partition alloc by default, whereas this moves it to the malloc allocator.

 public:
     static const int maxDepth = 1000;
 
     virtual ~JSONValue() { }
 
-    static PassRefPtr<JSONValue> null()
+    static std::unique_ptr<JSONValue> null()
     {
-        return adoptRef(new JSONValue());
+        return wrapUnique(new JSONValue());
     }
 
     typedef enum {
@@ -106,19 +109,19 @@ private:
 class PLATFORM_EXPORT JSONBasicValue : public JSONValue {
 public:
 
-    static PassRefPtr<JSONBasicValue> create(bool value)
+    static std::unique_ptr<JSONBasicValue> create(bool value)
     {
-        return adoptRef(new JSONBasicValue(value));
+        return wrapUnique(new JSONBasicValue(value));
     }
 
-    static PassRefPtr<JSONBasicValue> create(int value)
+    static std::unique_ptr<JSONBasicValue> create(int value)
     {
-        return adoptRef(new JSONBasicValue(value));
+        return wrapUnique(new JSONBasicValue(value));
     }
 
-    static PassRefPtr<JSONBasicValue> create(double value)
+    static std::unique_ptr<JSONBasicValue> create(double value)
     {
-        return adoptRef(new JSONBasicValue(value));
+        return wrapUnique(new JSONBasicValue(value));
     }
 
     bool asBoolean(bool* output) const override;
@@ -143,14 +146,14 @@ private:
 
 class PLATFORM_EXPORT JSONString : public JSONValue {
 public:
-    static PassRefPtr<JSONString> create(const String& value)
+    static std::unique_ptr<JSONString> create(const String& value)
     {
-        return adoptRef(new JSONString(value));
+        return wrapUnique(new JSONString(value));
     }
 
-    static PassRefPtr<JSONString> create(const char* value)
+    static std::unique_ptr<JSONString> create(const char* value)
     {
-        return adoptRef(new JSONString(value));
+        return wrapUnique(new JSONString(value));
     }
 
     bool asString(String* output) const override;
@@ -166,22 +169,27 @@ private:
 
 class PLATFORM_EXPORT JSONObject : public JSONValue {
 private:
-    typedef HashMap<String, RefPtr<JSONValue>> Dictionary;
+    typedef HashMap<String, std::unique_ptr<JSONValue>> Dictionary;
 
 public:
     typedef Dictionary::iterator iterator;
     typedef Dictionary::const_iterator const_iterator;
 
-    static PassRefPtr<JSONObject> create()
+    static std::unique_ptr<JSONObject> create()
     {
-        return adoptRef(new JSONObject());
+        return wrapUnique(new JSONObject());
     }
 
-    static PassRefPtr<JSONObject> cast(PassRefPtr<JSONValue> value)
+    static JSONObject* cast(JSONValue* value)
     {
         if (!value || value->getType() != TypeObject)
             return nullptr;
-        return adoptRef(static_cast<JSONObject*>(value.leakRef()));
+        return static_cast<JSONObject*>(value);
+    }
+
+    static std::unique_ptr<JSONObject> cast(std::unique_ptr<JSONValue> value)
+    {
+        return wrapUnique(JSONObject::cast(value.release()));
     }
 
     void writeJSON(StringBuilder* output) const override;
@@ -191,33 +199,29 @@ public:
     void setBoolean(const String& name, bool);
     void setNumber(const String& name, double);
     void setString(const String& name, const String&);
-    void setValue(const String& name, PassRefPtr<JSONValue>);
-    void setObject(const String& name, PassRefPtr<JSONObject>);
-    void setArray(const String& name, PassRefPtr<JSONArray>);
+    void setValue(const String& name, std::unique_ptr<JSONValue>);
+    void setObject(const String& name, std::unique_ptr<JSONObject>);
+    void setArray(const String& name, std::unique_ptr<JSONArray>);
 
     iterator find(const String& name);
     const_iterator find(const String& name) const;
     bool getBoolean(const String& name, bool* output) const;
     template<class T> bool getNumber(const String& name, T* output) const
     {
-        RefPtr<JSONValue> value = get(name);
+        JSONValue* value = get(name);
         if (!value)
             return false;
         return value->asNumber(output);
     }
     bool getString(const String& name, String* output) const;
-    PassRefPtr<JSONObject> getObject(const String& name) const;
-    PassRefPtr<JSONArray> getArray(const String& name) const;
-    PassRefPtr<JSONValue> get(const String& name) const;
+    JSONObject* getObject(const String& name) const;
+    JSONArray* getArray(const String& name) const;
+    JSONValue* get(const String& name) const;
 
     bool booleanProperty(const String& name, bool defaultValue) const;
 
     void remove(const String& name);
 
-    iterator begin() { return m_data.begin(); }
-    iterator end() { return m_data.end(); }
-    const_iterator begin() const { return m_data.begin(); }
-    const_iterator end() const { return m_data.end(); }
     ~JSONObject() override;
 
 protected:
@@ -232,19 +236,21 @@ private:
 
 class PLATFORM_EXPORT JSONArray : public JSONValue {
 public:
-    typedef Vector<RefPtr<JSONValue>>::iterator iterator;
-    typedef Vector<RefPtr<JSONValue>>::const_iterator const_iterator;
-
-    static PassRefPtr<JSONArray> create()
+    static std::unique_ptr<JSONArray> create()
     {
-        return adoptRef(new JSONArray());
+        return wrapUnique(new JSONArray());
     }
 
-    static PassRefPtr<JSONArray> cast(PassRefPtr<JSONValue> value)
+    static JSONArray* cast(JSONValue* value)
     {
         if (!value || value->getType() != TypeArray)
             return nullptr;
-        return adoptRef(static_cast<JSONArray*>(value.leakRef()));
+        return static_cast<JSONArray*>(value);
+    }
+
+    static std::unique_ptr<JSONArray> cast(std::unique_ptr<JSONValue> value)
+    {
+        return wrapUnique(JSONArray::cast(value.release()));
     }
 
     ~JSONArray() override;
@@ -255,24 +261,19 @@ public:
     void pushInt(int);
     void pushNumber(double);
     void pushString(const String&);
-    void pushValue(PassRefPtr<JSONValue>);
-    void pushObject(PassRefPtr<JSONObject>);
-    void pushArray(PassRefPtr<JSONArray>);
+    void pushValue(std::unique_ptr<JSONValue>);
+    void pushObject(std::unique_ptr<JSONObject>);
+    void pushArray(std::unique_ptr<JSONArray>);
 
-    PassRefPtr<JSONValue> get(size_t index);
+    JSONValue* get(size_t index) const;
     unsigned length() const { return m_data.size(); }
 
-    iterator begin() { return m_data.begin(); }
-    iterator end() { return m_data.end(); }
-    const_iterator begin() const { return m_data.begin(); }
-    const_iterator end() const { return m_data.end(); }
-
 protected:
     void prettyWriteJSONInternal(StringBuilder* output, int depth) const override;
 
 private:
     JSONArray();
-    Vector<RefPtr<JSONValue>> m_data;
+    Vector<std::unique_ptr<JSONValue>> m_data;
 };
 
 PLATFORM_EXPORT void escapeStringForJSON(const String&, StringBuilder*);