Paint Profiler: fix right boundary of selection window

- use "open" type for right end-point of selection interval (i.e. "[)",
    exlude the end value)
- adjust window calculation to better match actual bars in the overview.

BUG=426147

Review URL: https://codereview.chromium.org/676663002

git-svn-id: svn://svn.chromium.org/blink/trunk@184256 bbb929c8-8fbe-4397-9dbb-9b2b20218538