[rAC, OSX] Fix placeholder text font.

Omnibox placeholder text should use the same font as the text used
for field values.

BUG=347316
R=macourteau@chromium.org

Review URL: https://codereview.chromium.org/187383008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256023 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256023
Override PreDispatchEvent() and PostDispatchEvent() in RootView

In RootView, override the EventDispatcherDelegate functions
PreDipatchEvent() and PostDispatchEvent(). This allows us to
remove the unnecessary private helper function
RootView::DispatchEventToTarget() by replacing all 
of its calls with calls to 
EventDispatcherDelegate::DispatchEvent() instead.

BUG=348102
TEST=none

Review URL: https://codereview.chromium.org/176963005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256024 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256024