Minor defense-in-depth tweak. end - start + 1 can actually go negative if start==0 and end==9223372036854775807, i.e. the full positive range of a 64-bit signed int.
Minor defense-in-depth tweak. end - start + 1 can actually go negative if
start==0 and end==9223372036854775807, i.e. the full positive range of a
64-bit signed int.

BUG=NONE
TEST=NONE

Review URL: http://codereview.chromium.org/346003

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@30363 0039d316-1c4b-4281-b951-d872f2087c98

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