AU: ApplyMap utility function

AU: ApplyMap utility function

ApplyMap takes a vector<ValueType> and a map of
ValueType->ValueType. For each object in the collection that is a key
in the map, replace that element with the corresponding value in the
map.

E.g. ApplyMap({1, 2, 3, 4, 5}, {3->6, 5->7, 8->10}) changes the
collection to be: {1, 2, 6, 4, 7}.

BUG=7294
TEST=attached unittest

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=cc92cd3

[petkov, 2010-10-05 22:00:34]

LGTM w/ a couple of suggestions.

http://codereview.chromium.org/3530011/diff/2001/3001
File utils.h (right):

http://codereview.chromium.org/3530011/diff/2001/3001#newcode190
utils.h:190: if (MapContainsKey(the_map, *it)) {
Why not invoke the_map->find once, and if it doesn't return map::end, set the
second element...

http://codereview.chromium.org/3530011/diff/2001/3002
File utils_unittest.cc (right):

http://codereview.chromium.org/3530011/diff/2001/3002#newcode191
utils_unittest.cc:191: collection.insert(collection.end(),
move this to the vector constructor:

vector<int> collection(initial_values, initial_values +
arraysize(initial_values));

[adlr, 2010-10-05 23:56:59]

thanks. fixed and pushed