Port some things in browser/{download,history}, minor things in common....

chrome/browser/history/visit_tracker.cc

Index: chrome/browser/history/visit_tracker.cc
===================================================================
--- chrome/browser/history/visit_tracker.cc	(revision 2786)
+++ chrome/browser/history/visit_tracker.cc	(working copy)
@@ -11,8 +11,8 @@
 // When the list gets longer than 'MaxItems', CleanupTransitionList will resize
 // the list down to 'ResizeTo' size. This is so we only do few block moves of
 // the data rather than constantly shuffle stuff around in the vector.
-static const int kMaxItemsInTransitionList = 96;
-static const int kResizeBigTransitionListTo = 64;
+static const size_t kMaxItemsInTransitionList = 96;
+static const size_t kResizeBigTransitionListTo = 64;
 COMPILE_ASSERT(kResizeBigTransitionListTo < kMaxItemsInTransitionList,
                max_items_must_be_larger_than_resize_to);