Implement comparison operators for base::Value

base/values.h

Index: base/values.h
diff --git a/base/values.h b/base/values.h
index f74f543280e97b0372aa6b68e16f334796f3fbba..95d5d1c2baa280ed470f51ddcfab63af8788cc4b 100644
--- a/base/values.h
+++ b/base/values.h
@@ -161,11 +161,24 @@ class BASE_EXPORT Value {
   // Preferred version of DeepCopy. TODO(estade): remove the above.
   std::unique_ptr<Value> CreateDeepCopy() const;
 
+  // Comparison operators so that Values can easily be used with standard
+  // library algorithms and associative containers.
+  BASE_EXPORT friend bool operator==(const Value& lhs, const Value& rhs);
+  BASE_EXPORT friend bool operator!=(const Value& lhs, const Value& rhs);
+  BASE_EXPORT friend bool operator<(const Value& lhs, const Value& rhs);
+  BASE_EXPORT friend bool operator>(const Value& lhs, const Value& rhs);
+  BASE_EXPORT friend bool operator<=(const Value& lhs, const Value& rhs);
+  BASE_EXPORT friend bool operator>=(const Value& lhs, const Value& rhs);
+
   // Compares if two Value objects have equal contents.
+  // DEPRECATED, use operator==(const Value& lhs, const Value& rhs) instead.
+  // TODO(crbug.com/646113): Delete this and migrate callsites.
   bool Equals(const Value* other) const;
 
   // Compares if two Value objects have equal contents. Can handle NULLs.
   // NULLs are considered equal but different from Value::CreateNullValue().
+  // DEPRECATED, use operator==(const Value& lhs, const Value& rhs) instead.
+  // TODO(crbug.com/646113): Delete this and migrate callsites.
   static bool Equals(const Value* a, const Value* b);
 
  protected: