base: Add three helper functions to Values API.

content/renderer/v8_value_converter.cc

Index: content/renderer/v8_value_converter.cc
diff --git a/content/renderer/v8_value_converter.cc b/content/renderer/v8_value_converter.cc
index d2c21cd2cc10ae3fcab2d4365873a8f0f93ae73b..08cc961a3a0b4fefd6c7c7dacc574308bcc2cb2e 100644
--- a/content/renderer/v8_value_converter.cc
+++ b/content/renderer/v8_value_converter.cc
@@ -119,7 +119,7 @@ Value* V8ValueConverter::FromV8ValueImpl(v8::Handle<v8::Value> val) const {
   CHECK(!val.IsEmpty());
 
   if (val->IsNull())
-    return Value::CreateNullValue();
+    return base::NullValue();
 
   if (val->IsBoolean())
     return Value::CreateBooleanValue(val->ToBoolean()->Value());
@@ -136,7 +136,7 @@ Value* V8ValueConverter::FromV8ValueImpl(v8::Handle<v8::Value> val) const {
   }
 
   if (allow_undefined_ && val->IsUndefined())
-    return Value::CreateNullValue();
+    return base::NullValue();
 
   if (allow_date_ && val->IsDate()) {
     v8::Date* date = v8::Date::Cast(*val);
@@ -156,7 +156,7 @@ Value* V8ValueConverter::FromV8ValueImpl(v8::Handle<v8::Value> val) const {
     return FromV8Object(val->ToObject());
 
   LOG(ERROR) << "Unexpected v8 value type encountered.";
-  return Value::CreateNullValue();
+  return base::NullValue();
 }
 
 ListValue* V8ValueConverter::FromV8Array(v8::Handle<v8::Array> val) const {