How to make the bookmark bar of Google Chrome bigger?

Officially no. There are workarounds though, like grouping bookmarks in folders or using extensions.

Some ideas of extensions: Bookmark Bar Switcher which lets you switch between multiple bookmark bars or Iconized Bookmarks Bar which helps you gain space on the bookmarks bar by adding icons instead of text.

Simple answer is, it's not possible. If you want to check out all of the Google Chrome bookmark extensions, just search Google's official Web Store for bookmarks.

Your best bet is to sort them into folders and name the folders short one word names. This is what I did when I realized that I was running out of space.

Here is example of my Chrome bookmark bar:

If you want to save space, just use the icons by entering in blank names for the bookmarks you often use on your bookmark bar. :)