ParseDouble: allow validation only.

This change also updates documentation for Parse(Ui|I)nt functions
which recently had a corresponding change applied.

Bug: 110758329
Test: libbase_test
Change-Id: I4842c0500a6e49498eeb8a63d1117c06727fffdf
diff --git a/parsedouble_test.cpp b/parsedouble_test.cpp
index 8734c42..797a370 100644
--- a/parsedouble_test.cpp
+++ b/parsedouble_test.cpp
@@ -35,4 +35,9 @@
   ASSERT_FALSE(android::base::ParseDouble("3.0", &d, -1.0, 2.0));
   ASSERT_TRUE(android::base::ParseDouble("1.0", &d, 0.0, 2.0));
   ASSERT_DOUBLE_EQ(1.0, d);
+
+  ASSERT_FALSE(android::base::ParseDouble("123.4x", nullptr));
+  ASSERT_TRUE(android::base::ParseDouble("-123.4", nullptr));
+  ASSERT_FALSE(android::base::ParseDouble("3.0", nullptr, -1.0, 2.0));
+  ASSERT_TRUE(android::base::ParseDouble("1.0", nullptr, 0.0, 2.0));
 }