DevTools: move DevToolsAgent/Client into content.

BUG=84078
TEST=

Review URL: http://codereview.chromium.org/7461019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93596 0039d316-1c4b-4281-b951-d872f2087c98
void RenderThread::WidgetHidden() {
  DCHECK(hidden_widget_count_ < widget_count_);
  hidden_widget_count_++;

  if (!content::GetContentClient()->renderer()->
          RunIdleHandlerWhenWidgetsHidden()) {
    return;
  }

  if (widget_count_ && hidden_widget_count_ == widget_count_)
    ScheduleIdleHandler(kInitialIdleHandlerDelayS);
}

void RenderThread::WidgetHidden() {
  DCHECK(hidden_widget_count_ < widget_count_);
  hidden_widget_count_++;

  if (!content::GetContentClient()->renderer()->
          RunIdleHandlerWhenWidgetsHidden()) {
    return;
  }

  if (widget_count_ && hidden_widget_count_ == widget_count_)
    ScheduleIdleHandler(kInitialIdleHandlerDelayS);
}
