Fix the documentation for the cache size policies.
Fix the documentation for the cache size policies.

Those were saying the size is specified in MB but in reality those were
in B.

BUG=96264
TEST=No more confused users.

Review URL: https://chromiumcodereview.appspot.com/9837039

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@128481 0039d316-1c4b-4281-b951-d872f2087c98

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