Split infobars.{cc,h} into separate pieces for the different classes defined within, so that each piece is shorter and clearer.

BUG=none
TEST=none
Review URL: http://codereview.chromium.org/6250057

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@73235 0039d316-1c4b-4281-b951-d872f2087c98
 void TranslateInfoBarBase::Layout() {
  InfoBarView::Layout();
 
   gfx::Size icon_ps = icon_->GetPreferredSize();
  icon_->SetBounds(InfoBarView::kHorizontalPadding,
      InfoBarView::OffsetY(this, icon_ps), icon_ps.width(), icon_ps.height());
 }

 void TranslateInfoBarBase::Layout() {
  InfoBar::Layout();
 
   gfx::Size icon_ps = icon_->GetPreferredSize();
  icon_->SetBounds(InfoBar::kHorizontalPadding, InfoBar::OffsetY(this, icon_ps),
      icon_ps.width(), icon_ps.height());
 }
