Fix long tooltips flashing like crazy under Windows.

Fix long tooltips flashing like crazy under Windows.

Tooltips longer than 1024 chars get truncated. However, to determine if the tooltip changed, the un-truncated new text was compared to the truncated old text. Thus, for long tooltips, the tooltip text was considered to be constantly changing, causing the tooltip to be destroyed and re-created constantly.

R=Ben Goodger, Darin Fisher
BUG=4754
TEST=Go to (for example) http://people.mozilla.org/~rdoherty/tooltips.html and check that the long tooltips do not flash on Windows (I used Vista).

[Ben Goodger (Google), 2009-10-07 23:43:56]

OK LGTM.

[Peter Kasting, 2009-10-07 23:52:30]

Thanks a ton for fixing this, it shows up a lot on the buildbot pages for long
commit messages :)

[darin (slow to review), 2009-10-07 23:52:30]

http://codereview.chromium.org/265003/diff/5001/4
File chrome/browser/renderer_host/render_widget_host_view_win.cc (right):

http://codereview.chromium.org/265003/diff/5001/4#newcode633
Line 633: tooltip_text.substr(0, kMaxTooltipLength);
style nit:

const std::wstring& new_tooltip_text =
    tooltip_text.substr(0, kMaxTooltipLength);

when wrapping a line, indent the next line by 4 white spaces.  i also recommend
making the temporary be a reference type.

[Simon Radford, 2009-10-08 03:47:24]

Fixed comments, and added localized, better truncation including ellipsis (...)
and break-on-word-boundary.

[darin (slow to review), 2009-10-08 06:26:24]

LGTM

[darin (slow to review), 2009-10-08 06:50:13]

committed as r28383