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
bool RenderView::runModalConfirmDialog(
    WebFrame* frame, const WebString& message) {
  return RunJavaScriptMessage(ui::MessageBoxFlags::kIsJavascriptConfirm,
                              message,
                              string16(),
                              frame->document().url(),
                              NULL);
}

bool RenderView::runModalConfirmDialog(
    WebFrame* frame, const WebString& message) {
  return RunJavaScriptMessage(ui::MessageBoxFlags::kIsJavascriptConfirm,
                              message,
                              string16(),
                              frame->document().url(),
                              NULL);
}
