This CL fixes issue 17468 - Regression: Extra white rectangle showing when mouse hovering on every web page
This CL fixes issue 17468 - Regression: Extra white rectangle showing when mouse hovering on every web page

Should check tooltip text against empty before adding Unicode Marks for directionality.

BUG=http://crbug.com/17468
BUG=http://crbug.com/17176
BUG=http://crbug.com/5996
TEST= open a webpage, mouse over plain text area, empty square should not show up as tooltip. 
Review URL: http://codereview.chromium.org/159222

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@21353 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser