Reviewed by Eric Seidel.

        Fix [Chromium] drop down menu letter selection, skip selections
        https://bugs.webkit.org/show_bug.cgi?id=28205

        Not auto-testable since it is chromim platform specific code, and it involves sending a keyboard
        event to the popup, which is not possible (eventSender sends the key
        events through webview, we want to go through the webwidget).

        * manual-tests/keyboard_select_elements_with_same_beginning.html: Added.
        * platform/chromium/PopupMenuChromium.cpp:
        (WebCore::isCharacterTypeEvent): style change.
        (WebCore::PopupListBox::handleKeyEvent): typeAheadFind should be called only when the event is
        a character type event to avoid calling twice for English.
        (WebCore::PopupListBox::typeAheadFind): remove unnecessary checking of isCharacterTypeEvent() since the whole function is only called under that condition.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@47150 268f45cc-cd09-0410-ab3c-d52691b4dbfc