Add missing operator<() to CFX_RetainPtr.

Use std::less<>() rather than a direct ptr1 < ptr2 comparison to
be strictly correct in face of unspecified behaviour when ptr1 and
ptr2 don't point within the same "object" (e.g. segment of memory
on a brain-dead segmented architecture).

This will allow their use as keys in maps.

Review-Url: https://codereview.chromium.org/2616683002

1 files changed, 8 insertions, 0 deletions

diff --git a/core/fxcrt/cfx_retain_ptr_unittest.cpp b/core/fxcrt/cfx_retain_ptr_unittest.cpp
index f9a4ecb74f..3168b5a4c7 100644
--- a/core/fxcrt/cfx_retain_ptr_unittest.cpp
+++ b/core/fxcrt/cfx_retain_ptr_unittest.cpp
@@ -225,6 +225,14 @@ TEST(fxcrt, RetainPtrNotEquals) {
   EXPECT_TRUE(obj1_ptr1 != obj2_ptr1);
 }
 
+TEST(fxcrt, RetainPtrLessThan) {
+  PseudoRetainable objs[2];
+  CFX_RetainPtr<PseudoRetainable> obj1_ptr(&objs[0]);
+  CFX_RetainPtr<PseudoRetainable> obj2_ptr(&objs[1]);
+  EXPECT_TRUE(obj1_ptr < obj2_ptr);
+  EXPECT_FALSE(obj2_ptr < obj1_ptr);
+}
+
 TEST(fxcrt, RetainPtrBool) {
   PseudoRetainable obj1;
   CFX_RetainPtr<PseudoRetainable> null_ptr;