[Mac] Do not resize devtools when showing if it is already open.
[Mac] Do not resize devtools when showing if it is already open.

BUG=34494
TEST=Open devtools and resize.  Right-click on the webpage and "Inspect element."  Devtools should not resize to its original size.
Review URL: http://codereview.chromium.org/565040

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@38770 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