Added RefCountedMallocedMemory

Which takes ownership over a chunk of memory allocated with malloc or calloc
and must then be freed using free().

Review URL: https://codereview.chromium.org/78603002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236675 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236675
Refactor taskbar anchoring tests on Windows to match Mac tests.

This affects both AppListWinUnitTest and AppListPositionerUnitTest. It
now uses named constants and expressions instead of hard-coded numbers
in the tests. It also uses abstractions to set up state rather than
manually supplying the parameters in each test case.

Also moved app_list_win's FindAnchorPoint into the AppListWin class.

BUG=317944

Review URL: https://codereview.chromium.org/80053003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236676 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236676