Cleaning up base::Value assignment.

base/values.cc

Index: base/values.cc
diff --git a/base/values.cc b/base/values.cc
index 25a25fba6e489ce8420954941598dace98da8f38..6728e55519a77e42ab73c587a0d5b2ff8bd83e95 100644
--- a/base/values.cc
+++ b/base/values.cc
@@ -173,27 +173,21 @@ Value::Value(std::vector<char>&& in_blob) : type_(Type::BINARY) {
 }
 
 Value& Value::operator=(const Value& that) {
-  if (this != &that) {
-    if (type_ == that.type_) {
-      InternalCopyAssignFromSameType(that);
-    } else {
-      InternalCleanup();
-      InternalCopyConstructFrom(that);
-    }
+  if (type_ == that.type_) {
+    InternalCopyAssignFromSameType(that);
+  } else {
+    // This is not a self assignment because the type_ doesn't match.
+    InternalCleanup();
+    InternalCopyConstructFrom(that);
   }
 
   return *this;
 }
 
 Value& Value::operator=(Value&& that) {
-  if (this != &that) {
-    if (type_ == that.type_) {
-      InternalMoveAssignFromSameType(std::move(that));
-    } else {
-      InternalCleanup();
-      InternalMoveConstructFrom(std::move(that));
-    }
-  }
+  DCHECK(this != &that) << "attempt to self move assign.";
+  InternalCleanup();
+  InternalMoveConstructFrom(std::move(that));
 
   return *this;
 }
@@ -534,6 +528,8 @@ void Value::InternalMoveConstructFrom(Value&& that) {
 }
 
 void Value::InternalCopyAssignFromSameType(const Value& that) {
+  // TODO(crbug.com/646113): make this a DCHECK once base::Value does not have
+  // subclasses.
   CHECK_EQ(type_, that.type_);
 
   switch (type_) {
@@ -563,32 +559,6 @@ void Value::InternalCopyAssignFromSameType(const Value& that) {
   }
 }
 
-void Value::InternalMoveAssignFromSameType(Value&& that) {
-  CHECK_EQ(type_, that.type_);
-
-  switch (type_) {
-    case Type::NONE:
-    case Type::BOOLEAN:
-    case Type::INTEGER:
-    case Type::DOUBLE:
-      InternalCopyFundamentalValue(that);
-      return;
-
-    case Type::STRING:
-      *string_value_ = std::move(*that.string_value_);
-      return;
-    case Type::BINARY:
-      *binary_value_ = std::move(*that.binary_value_);
-      return;
-    case Type::DICTIONARY:
-      *dict_ptr_ = std::move(*that.dict_ptr_);
-      return;
-    case Type::LIST:
-      *list_ = std::move(*that.list_);
-      return;
-  }
-}
-
 void Value::InternalCleanup() {
   CHECK(alive_);