Give the "update available" dialog a better title.
This also updates the strings involved to not use IDS_PRODUCT_NAME, per current
l10n guidelines. Their descriptions are (hopefully) improved as well.
This also collapses the disparate users of the string "Not now" into using one
common generic string.
BUG=629184
TEST=Select the "Update Chrome" menu entry and check that the dialog title is not just "Google Chrome".
Review-Url: https://codereview.chromium.org/2178103002
Cr-Commit-Position: refs/heads/master@{#408480}
10 files changed
