Cleanup deprecated Java 5/6/7 code and types.

[MukjepScarlet]

Example:

    public boolean onFileDialog(CefBrowser browser, FileDialogMode mode, String title,
            String defaultFilePath, Vector<String> acceptFilters, Vector<String> acceptExtensions,
            Vector<String> acceptDescriptions, CefFileDialogCallback callback);

Vector -> Collection/Iterable

/**
 * Callback interface for CefBrowserHost::RunFileDialog. The methods of this
 * class will be called on the browser process UI thread.
 */
public interface CefRunFileDialogCallback {
    /**
     * Called asynchronously after the file dialog is dismissed. If the selection
     * was successful filePaths will be a single value or a list of values
     * depending on the dialog mode. If the selection was cancelled filePaths
     * will be empty.
     *
     * @param filePaths list of file paths or empty list.
     */
    void onFileDialogDismissed(Vector<String> filePaths);
}

Should be

@FunctionalInterface
public interface CefRunFileDialogCallback {
    void onFileDialogDismissed(Collection<String> filePaths)
}

Some inner classes can be static classes.

[magreenblatt]

Sounds reasonable. We might also pick a more reasonable minimum supported version (which is currently documented as Java 7).