This has been changed since v32, thanks to @Daniel Alexiuc & @Thanatos for their comments.
Current (≥ v32)
At the top of the "Network" tab of DevTools, there's a checkbox to switch on the "Preserve log" functionality. If it is checked, the network log is preserved on page load.
![Chrome v33 DevTools Network Tab: Preserve Log](https://i.stack.imgur.com/cFuNP.png)
The little red dot on the left now has the purpose to switch network logging on and off completely.
Older versions
In older versions of Chrome (v21 here), there's a little, clickable red dot in the footer of the "Network" tab.
![Chrome v22 DevTools Network Tab: Preserve Log Upon Navigation](https://i.stack.imgur.com/tSUP0.png)
If you hover over it, it will tell you, that it will "Preserve Log Upon Navigation" when it is activated. It holds the promise.
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